Avoids an NPE if the preview manager's server is null
Avoids deadlocking the UI when disconnecting an ldap connection profile

* See inline comment
TEIIDDES-1956: Refactor not refactoring some references

* To minimise edits in the refactored dependent models, a prefix is
  prepended to the text being replaced in SQL statements. These prefixes
  consist of punctuation marks commonly preceding model names in such
  statements, such as spaces, commas etc...

* The opening bracket needs to be included if the model name
  to-be-refactored is used in a function, eg. convert(Model.blah.id...)
TEIIDDES-1944: check jboss server prior to refreshing teiid instance

* Avoids throwing an exception when refreshing a stopped teiid instance
* Displays sensible error message instead
JBIDE-16133: Provide better feedback for incorrect admin password

* JBoss[7]ServerUtil
* TeiidServerAdapterFactory
 * Rather than catching JBoss exceptions (may be caused by incorrect
   security credentials) throw them instead and force UI components to
   catch and process them

* TeiidServer
 * Better handle exceptions thrown when failing to connect to teiid instance

* TeiidServerEditor
* TeiidParentServerListener
 * Rather than just logging exceptions thrown when initialising the teiid
   instance, get the exception back to the user

* DqpPlugin
 * API for handling exceptions by displaying them using an ErrorDialog
 * This is not ideal given that the DqpPlugin is technically a non-UI
   plugin despite depending on org.eclipse.ui.
 * At some point, this needs refactoring to set a UI provider for displaying
   exceptions in the UI.
TEIIDDES-1949 added message dialog to warn user that function definition is too complex and directs them to workaround.
TEIIDDES-1929: Stricter policy on allowing deletions with open editors

* When deleting, resources are unloaded and closed. This can lead to odd
  updates to open editors

* Delete is the only refactoring to allow the operation whilst editors are
  open. This is fine if an editor for the resource being deleted is open
  since the editor gets closed anyway. However, it can be a problem for
  related resource editors, especially if the delete is cancelled. The
  resources are not reloaded and the editor never refreshed

* Check for open editors of related resources and just get the user to
  close it first before proceeding.
TEIIDDES-1962 fixed wrong variable value checks.
TEIIDDES-1963 Removed result set tab from function option panel.
 * Fixed enablement issues with NULL result set name for procedures