Add ATNSimulator.clearDFA, and implement for LexerATNSimulator and ParserATNSimulator
Simplify the GrammarAST constructors, and correct the token start/stop index not being set
Add utility method ATNConfigSet.getAlts
Merge pull request #584 from sharwell/clear-dfa

Add ATNSimulator.clearDFA
Merge pull request #585 from sharwell/grammar-ast

Simplify the GrammarAST constructors
Merge pull request #586 from sharwell/getalts

Add utility method ATNConfigSet.getAlts
Add the SemanticContext.Operator base class to provide consistent API access to the operands of AND and OR contexts
Merge pull request #587 from sharwell/getoperands

Add the SemanticContext.Operator interface
initial profiler
making a dump routine
precedence option now set as real option not text appended to rule refs.  Added new options to rule/token refs to include pos info. add a test, which currently fails. options on rule refs were not being checked! All previous tests pass.
Grammar elements with charPos, line, charIndex options get rewritten with a new GrammarToken object that holds this original info. Introduce constant for element options. Add real unit tests.
starting up work again, add tests
better testing; all data for decision in 1 object
aggregate profiling data per decision.
major augmentation of info I track. More precise info.  Altered overrides to track better.
add API to Parser to set profiling on or off.
improved dump info, update test.
improved dump info, update test.
compute better cost function