PRD-4691: Handle formulas with unbalanced parenthesis in inner formulas.  Added several test cases.
PRD-4691: Check count before indexing.
PRD-4691: Allow for tab between textfields and have parameter field evaluated properly.  Added some null guards.
Merge pull request #262 from pentaho-skarmali/PRD_4761_handle_tabbing_formula_parameter_fields

PRD-4691: Allow for tab between textfields and have parameter field eval...
Merge pull request #261 from pentaho-skarmali/PRD_4691_nested_function

Prd 4691 nested function