Add simple select statement to xtext grammar.

The grammar supports a simple select statement with only one column selection.
Add multi-column selection to select statement.
Remove build output files from repository.
Ignore build output and generated sources.
Add custom formatting.

The formatter wraps each sql statement to one single line.
Make keywords case insensitive.
Fix SelectList attribute names.
Initial commit of parser unit test. Not yet complete.
Code clean up.