Provides unit testing for DDL / TSQL sequencers acting together

* *.json
 * Fixes the path expressions of the sequencers so that the TSQL sequencer
   is initialised when a [teiid]ddl:queryExpression property is added to
   the repository

* TeiidSql.cnd
* TeiidSqlLexicon
* TeiidCndGenerator
* TeiidSqlSequencer
 * Rather than storing the teiid version in the output node, it would be
   better to attach it to each language object as it is sequenced

* TeiidVersionProvider
 * The Teiid version is vital to the correct parsing of SQL statements so
   should be obtainable from an easily accessible source. Likewise, it
   should be easily updateable. Thus this provider in the spi simply stores
   the current teiid version value, allowing it to be accessed from the
   sequencers as well as any other part of the application

* Refactors tests to better co-ordinate abstract parent classes and reduce
  method duplication. Also, adds Sequencers tests for testing the
  sequencing of DDL statements using both sequencers