[PDI-10529] Append to OPT environment variable

Append arguments to OPT variable instead of overwrite in control scripts.
Allows Java command line arguments to be set from external sources in a standardized manner.
Merge pull request #621 from hudak/PDI-105297

[PDI-105297] Append to OPT environment variable in control scripts
[PDI-12472] - JSON Output Functionality Changes Significantly in 5.1 from 5.0

Rolling back to a known good state
Merge pull request #622 from rfellows/dev

[PDI-12472] - JSON Output Functionality Changes Significantly in 5.1 from 5.0
[PDI-12482] - Reverting Encr arg check as 2 and only 2 arguments are always used
Merge pull request #625 from brosander/PDI-12482-master

[PDI-12482] - Reverting Encr arg check as 2 and only 2 arguments are alw...
[PDI-10568]Install ESAPI properties to ~/.kettle

If ESAPI properties are not otherwise defined for the JVM, install defaults to $HOME/.kettle/esapi
Set this directory as the default esapi resources directory.
Failure to install will fall back to using defaults from the classloader (previous configuration method).

http://jira.pentaho.com/browse/PDI-10568