Explicitly enable/disable codegen/orca while running installcheck-good and installcheck-bugbuster (#1213)

While running installcheck , we are not explicitly setting codegen or orca to "off" . This causes confusion and also is prone to bugs where the feature may be turned "on" before running installcheck.

This commit explicitly turns off the feature during installcheck-good and installcheck-bugbuster.

Thanks,
Nikhil & Nikos

- We add 4 flavors of installcheck-bugbuster jobs
- installcheck-bugbuster jobs depends on installcheck-good jobs passing
- Package job depends on installcheck-bugbuster jobs passing

[#129755231]
Signed-off-by: NNikhil Kak <nkak@pivotal.io>

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 should at least unblock testing.
In the long run, packaging of Greenplum Database should be more
self-contained, so as to further decouple the test and build process.

* Always build codegen with latest ORCA

* Ensure consistency between source and artifact

We apply the same `passed` condition to both Greenplum Database source
code and the compiled binaries. This ensures the tests receive
consistent pairs of inputs.

* Codegen always builds with ORCA

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.

https://gporca.ci.pivotalci.info/pipelines/gpdb_perfSigned-off-by: NJesse Zhang <jzhang@pivotal.io>

PR pipeline is at: https://gporca.ci.pivotalci.info/pipelines/gpdb_pr

- Add new pullrequest_resource gpdb_pr through docker image at `pivotaldata/pr-resource:latest`
- Add github pull request pipeline `pr_pipeline.yml`
Signed-off-by: NKarthikeyan Jambu Rajaraman <krajaraman@pivotal.io>

Signed-off-by: NShreedhar Hardikar <shardikar@gmail.com>

By using authenticated access

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