PDI-10467 - Data Grid step: Meta tab values for all columns get lost upon going to Data tab.

What was done:
1) Removed extra method call
PDI-10828 - Variables in Commit Size for Update, Insert/Update and Delete
Steps are not accepted

What was done:
1)changed Meta classes to support string value
2) changed step classes to convert string to value with respect to
variables
3) changed dialog classes to avoid unnecessary convertions
4) added unit tests
PDI-10828 - Variables in Commit Size for Update, Insert/Update and Delete
Steps are not accepted

UI changes to mark fields that they support variables
PDI-10828 - Variables in Commit Size for Update, Insert/Update and Delete Steps are not accepted

What was done:
1) changed the way bug is fixed according to Matt Burgess's notes
2) added backward compatibility support
[PDI-7564] HTTP Client logs Status 204 as an error (204: No Content)
PDI-689 - Copy / paste of steps doesn't copy error handling information
[PDI-7374] PDI REST Client should not log a status 204 as an error.
PDI-10862 - Synchronized stepListeners collection
Fix warnings and checkstyle errors introduced post-Matt C's changes.
PDI-11151 - Check for sorted keys after LDAP connection
PDI-10936 - add unit test and use JUnit4
PDI-10936 return false if processRow input is empty
[PDI-10936] Apply formatting and adding JUnit4 wrapper
PDI-7243 - JSON Output Step throws NullPointerException when previewing no rows

fix added, junit tests

modified:   engine/src/org/pentaho/di/trans/steps/jsonoutput/JsonOutput.java
modified:   engine/src/org/pentaho/di/trans/steps/jsonoutput/JsonOutputData.java
PDI-11183 - JSONOutput fails when no input rows

fix added
Checkstyle repair
modified:   engine/src/org/pentaho/di/trans/steps/ldapinput/LDAPInput.java
PDI-7243 - JSON Output Step throws NullPointerException when previewing no rows

junit tests improved
PDI-8395 - JSON Output step only outputs last line of transformation if
append is not checked.

junit tests added
PDI-8395 - JSON Output step only outputs last line of transformation if
append is not checked.

fix added
PDI - 7243 - JSON Output Step throws NullPointerException when previewing no rows

Checkstyle for junit test, System.out removed