Move priority of ';' token to top.
Add operator table a la octave.el and ruby-mode.el.
Reformat the bnf->prec2 table.
Merge in the operator table.
Remove the 'resolvers' from bnf->prec2 fn call

At this point I have basically sanded down elixir-mode's grammar spec to
some pretty bare bones.
Move defrecord grammar to top.
Remove the operator table for now.
Remove COMMA and OP from list of block-opener keywords.
Remove SMIE rules no longer necessary.
Remove unused parameter from elixir-smie-next-token-no-lookaround.
Remove test of deprecated syntax.
Put back the one-line if statements.
Remove operator table.
Remove 'OP' from the gramar as it causes more problems than it's worth.
Add smie rule for after ';' tokens.
Remove smie-merge-prec2s call.
Merge pull request #75 from elixir-lang/rejigger-smie-grammar

Clean up several minor bugbears in elixir-smie.