fix poor function name: setTokenAssoc
add <options> notation to alt right after pipe. rename elementOption to ruleElementOption as it now can match options on alt.  Move AltAST to have options.
changed grammar to allow <assoc=right> on | operator for alt. still allowed on token refs but ignored. Simplified left-recursion elemination rules. see CHANGES.TXT Aug 7, 2013. BREAKING CHANGE. Must alter ternary op alts in grammars.
change ruleElementOption back to elementOption
Merge pull request #314 from parrt/reorg-left-recur-elim

Reorg left recur elim
Add regression test for #315 (already passes)
Merge pull request #318 from sharwell/test-315

Add regression test for #315 (already passes)
Update contributors.txt
Merge pull request #323 from cayhorstmann/patch-1

Update contributors.txt
fix null ptr exception as reported by Coverity
Merge pull request #327 from parrt/master

fix null ptr exception as reported by Coverity
rm print statement
resource leak fix from Coverity Scan
rm potential null ptr deref (Coverity)
make explicit that graphs must be EmptyContext, never null (Coverity)
avoid potential null ptr deref (Coverity)
rm unneeded null ptr check (Coverity)
fix cut-paste error (Coverity)
rm dead code (Coverity)
defined compareTo but not equals/hash (Coverity)