GH-102 Address issues stemming from ANTLR's generated parser
- Removes flexibility associated with logical operators 'not in', 'is null',
   now required to be passed in as either 'NOT IN', 'not in', 'IS NULL', 'is
- Fixes Join condition exception message
- Fixes function expression param index update
- Removes old generated parser/lexer classes
- Adds new test cases
GH-102 Minor wording change from code review.

Signed-off-by: Rodrigo Pastrana <Rodrigo.Pastrana@lexisnexis.com>
Merge pull request #104 from rpastrana/gh-102-ANTLR_parser_whitespace

GH-102 Address issues stemming from ANTLR's generated parser
GH-108-Ensure ANTLR generated code is process by build
Remove sqlparser/generated classes
Ensure generated classes are added to src files list

Signed-off-by: Rodrigo Pastrana <Rodrigo.Pastrana@lexisnexis.com>
GH-108 minor change from code review.

Signed-off-by: Rodrigo Pastrana <Rodrigo.Pastrana@lexisnexis.com>
Merge pull request #109 from rpastrana/GH-108-antlr-generatedcode

GH-108-Ensure ANTLR generated code is process by build