Modify build framework

* Renames eclipse build launcher

* build.xml
 * Ensures a clean always takes place prior to a build

* pom.xml
 * Refactor the destination for the ast nodes and the parser.
 * Renames the parser to Teiid8Parser, explicity showing this to be
   different to the Teiid7Parser
 * Some options seem to be ignored by mvn jjtree-javacc so all options
   included here as well as they are fully observed

* Teiid8Parser.jjt
 * Ensures that all ast nodes are created via jjtree even if there are
   just simple newNode() methods. Means that the node classes are parser
   aware and the parser is aware of their constant ids
Modify, fix and commit the ast nodes

* AST nodes created based on version 8.4 teiid code. Still need to be
  sure they are backward compatible with version 7.7

* AggregateSymbol
* WindowFunction
 * Examples of AST nodes which have changed their class hierarchy. To
   workaround this, the javacc template utilises a factory for constructing
   the nodes. The factory can key on the parser version and return the
   correct implementation of aggregate symbol.
 * Thus, an AggregateSymbol interface is used throughout and two different
   implementations (v7 and v8) created.

* TeiidParser
 * Interface covering all version implementations of parsers
 * AST nodes reference this interface to make them compatible across parser
   versions

* PropertiesUtil
* StringUtil
 * Utility methods brought directly from teiid code
WIP SQL7Parser