This commit fixes issues below:

extractContent() might forward NULL to marker.
ListBucket() fogets to delete keylist when errors happen.
contents in ListBucketResult are not cleared.
downloader is not destroyed in unit tests.
get_opt_s3() and truncate_options() in unit tests need to be freed.
xmlNodeGetContent() needs to be freed.
xml.ctxt->myDoc needs to be freed.
function for the XML library needs to be cleared.

Thanks to Kuien and Valgrind.

Backport below commits from upstream:

    commit 31edbadf
    Author: Tom Lane <tgl@sss.pgh.pa.us>
    Date:   Tue Jun 5 21:31:09 2007 +0000

        Downgrade implicit casts to text to be assignment-only, except for the ones
        from the other string-category types; this eliminates a lot of surprising
        interpretations that the parser could formerly make when there was no directly
        applicable operator.

        Create a general mechanism that supports casts to and from the standard string
        types (text,varchar,bpchar) for *every* datatype, by invoking the datatype's
        I/O functions.  These new casts are assignment-only in the to-string direction,
        explicit-only in the other, and therefore should create no surprising behavior.
        Remove a bunch of thereby-obsoleted datatype-specific casting functions.

        The "general mechanism" is a new expression node type CoerceViaIO that can
        actually convert between *any* two datatypes if their external text
        representations are compatible.  This is more general than needed for the
        immediate feature, but might be useful in plpgsql or other places in future.

        This commit does nothing about the issue that applying the concatenation
        operator || to non-text types will now fail, often with strange error messages
        due to misinterpreting the operator as array concatenation.  Since it often
        (not always) worked before, we should either make it succeed or at least give
        a more user-friendly error; but details are still under debate.

        Peter Eisentraut and Tom Lane

    commit bf940763
    Author: Tom Lane <tgl@sss.pgh.pa.us>
    Date:   Tue Mar 27 23:21:12 2007 +0000

        Fix array coercion expressions to ensure that the correct volatility is
        seen by code inspecting the expression.  The best way to do this seems
        to be to drop the original representation as a function invocation, and
        instead make a special expression node type that represents applying
        the element-type coercion function to each array element.  In this way
        the element function is exposed and will be checked for volatility.
        Per report from Guillaume Smet.

This seems to be leftovers from when gpcheckdb was in src/bin and
was written in C++. Nothing references this and the directory is
empty so remove.

This bug was introduced in fd2e045f.

Thanks to Shoaib Lari for pointing this out.

This patch slightly changes the way the demo cluster is built.
A gpinitdbsystem return code of 1 (warning) is ignored, and the script
exits with return code 0. Any error code greather than that is returned.
The Makefile is no longer ignoring errors.

This will fix #456.

The data directory and the TCP ports can be changed when "make cluster" is
executed to build the demo cluster:

DATADIRS=/tmp/gpdb-cluster MASTER_PORT=15432 PORT_BASE=25432 make cluster

This fixes #441 and #442

Also make the TCP port for the regression tests configurable.

Authors: Nikos Armenatzoglou and Shreedhar Hardikar.

GPMapreduce isn't threaded so -pthreads is a noop causing annoying
warning messages in clang.

This adds a new switch to autoconf, --enable-mapreduce, to connect
the GPMapreduce extension to the build. If set to on the mapreduce
extension in gpAux/extensions will be built and installed.  As a
side effect this will properly clean and distclean for gpfdist in
gpAux/extensions as well. Autoconf checks for libyaml since it's
a depedency for GPMapreduce.

This is the first stab at gpmapreduce, once in we can start moving
gpmapreduce back into src/bin and move the mapreduce test suite in
under gpAux/extensions.

Now s3ext supports all amazon s3 regions.
http://docs.aws.amazon.com/general/latest/gr/rande.html#s3_region

fix read_callback()
fix memleaks, thanks to cppcheck
check every pointer returned from malloc()
remove unused functions, add uri encoding codes
strftime()'s argument max includes the terminating null byte

Closes #488.

compatible with s3.amazonaws.com and s3-us-east-1.amazonaws.com regions
catch any exceptions thrown by C++ functions
set min and max values of threadnum and chunksize

and will move development to GPDB source tree after this.

This is first release and doesn't support write operation.
S3 has its own unittest with gtest

As gpfdist will now be part of the gpdb build by default, we may just
treat it as part of gpdb core.
* Integrate gpfdist configure file to the top level configure and
  changed necessary files to accomadate the changes.
* Modify travis.yml for gpfdist structural changes
* Update gpfdist.c to use GP_VERSION from pg_config.h

Fix warning issues from transform.c
* There were many prototype warnings that was being mentioned.
  Added a headerfile for missing prototype warnings, also included the
  structs into the headerfile.

Replace src/port/glob.c
* src/port/glob.c is dead code at the moment and can be safely replaced by
  the windows changes from gpfdist/port

Check for libyaml:
* disable transformations for gpfdist if not found.

This reverts commit e929d4d0.

I tried running this, and got a ton of errors. I don't think anyone's
used this for ages, so let's stop pretending that you might want to run
it. It might be a useful tool, as might some other style-checker or static
analysis tool, but this doesn't seem useful in its current state.

Users should use error log functionality for error handling in external tables
and during copy since it is more robust and reliable than the old error table
functionality.

Revert the VacAttrStats struct to look the same as in upstream. As a
consequence, we have to also revert the GPDB-specific changes to PostGIS
typanalyze functions. VacAttrStats is part of the public API for
type-specific typanalyze functions, so it's nice to revert that back the
way it is in the upstream, to make custom datatypes written for PostgreSQL
more easily portable to GPDB.

To my surprise, the VacAttrStats struct isn't currently used for anything,
so the changes to it were quite superfluous to begin with. That is to say,
we don't currently use type-specific typanalyze functions at all. That's
about to change, as part of a separate patch I'm working on to revert most
of analyze.c to use upstream code.

Also remove the unused VPgStatisticsStats struct, and the unnecessary
abstraction where VUpdateStats can be either VPgClassStats or
VPgStatisticsStats.

This version changes the spelling of the error message of violating a NOT
NULL-constraint, to match the message of the same error in the executor, so
those differences in regression test expected output can now be reverted.