TEIIDDES-1565: ClassLoader patch backported from version 8.0

* Allows a classloader to be set on SystemSource, necessary for invoking
  the function method classes. Designer requires this since the default
  plugin classloaders have no dependencies on the teiid client plugins.
TEIIDDES-1565: Remove unnecessary modules and directories
TEIIDDES-1565: Addition of designer source code
TEIIDDES-1565: Apply eclipse configuration to project

* Project and classpath configuration settings

* External tool builder for auto-generating the parser from the jj template

* Libraries copied in by maven for compilation of sources. Versions are
  stripped to allow build.properties to include them in the runtime

* Reconfiguration of pom xml to use tycho, auto-generate parser while in
  eclipse and build as a single plugin project rather than separate modules
TEIIDDES-1565: Fix clone methods

* Instead of returning generic Object, return the correct class
TEIIDDES-1565: Remove isFunction and isExpression methods

* No need for them and means adding superfluous extra methods to teiid
  classes
WIP