TEIIDDES-1839 Click on Add Button in Reconciler does nothing in some cases
TEIIDDES-1838 Inconsistent display of nulls in Reconciler
Add Preference to Toggle SHOWPLAN and DEBUG in Preview
Merge pull request #233 from mdrillin/TEIIDDES-JIRAS

TEIIDDES-1838, 1839, 1834
Merge pull request #234 from phantomjinx/8.2.x

Fixes ....
TEIIDDES-1848 Preview fails after manual undeployment of the preview vdb
Merge pull request #235 from mdrillin/TEIIDDES-1848

TEIIDDES-1848
TEIIDDES-1845 remove embedded help plugin
TEIIDDES-1835 Added "Clear Preview Artifacts" action to Teiid server action list
TEIIDDES-1837 Added hidden project and non-modeler project checks
TEIIDDES-1840 fixed isValidSelection() logic
TEIIDDES-1826 Designer doesn't yet support Flat File Connection Profile URL input option
Merge pull request #236 from mdrillin/8.2.x

TEIIDDES-1826 Designer doesn't yet support Flat File Connection Profile URL input option
TEIIDDES-1852 added null check for username & password values before adding to properties object
Avoid deadlock by using the same object to synchronise open calls

* Possible to have the UI thread taking ownership of the
  ModelWorkspaceManager with another thread owning the openLock. Thus, the
  2 threads can become deadlocked.
TEIIDDES-1457: Add a reference to the SYSADMIN external resource

* The SYSADMIN model in the System.vdb is never added to the set of
  external resources hence its functions are not available to the SQL
  parser and resolver.
Adds visualisation to execution plan view

* .project
 * External builder for zipping up the execution plan website data payload
   as its more efficient for java to unzip it into the temporary directory
   rather than copy each invidual file.

* Removes the old PlanToHTML.xsl which appears redundant

* Adds Visualisation tab to execution plan view, displaying a browser
  widget containing an html of the plan. Creates an execution-plan temp
  directory and unzips its javascripts, css and images files. Should only
  happen the first time an execution plan is requested.