GPORCA on/off
CODEGEN on/off

Also patch up a bug in ic_gpdb.bash to use GCC 6.2.0.

[#129755219]
Signed-off-by: NNikhil Kak <nkak@pivotal.io>

As per review comments in PR #1158.

* Setting up RSA key pair
* Enhancement to kernel parameters by changing sysctl.conf
* Changing ulimit values for opened files and number of processes
* Additional debug log in concourse for detecting parameter changes
* Add verification for prepare steps
* Make remote_run_scripts easier to use

[#130552319]
  * Automate VM provisioning with given VM size
  * Output the VM information, e.g. hostname, IP etc.
  * Be able to SSH to that VM from Pipeline.
  * Destroy VM.
Signed-off-by: NNikos Armenatzoglou <nikos.armenatzoglou@gmail.com>

This is an old version of PL/Java and the newer version is maintained in a separate
repo (https://github.com/greenplum-db/pljava). This removes the PL/Java directory, 
PL/Java tests, and all references to PL/Java.

Create GpcodegenBuild, GporcaBuild and GporcacodegenBuild builds to
support building GPDB with codegen, orca, and orca_and_codegen.

Refactor test_with_orca.py and build_with_orca.py
Extract the common piece out as GporcaCommon package.

Disable gpfdist tests with --disable-gpfdist option for configure,
because GPORCA doesn't impact the management utilities like gpfdist.