feature(grammar): allow key-value options

[just-boris]

Now you have ability to specify options in grammar file. It's enough for me, because I have to declare my module name in my file. I can do it in JSON file and I want to do it in BNF files as well.

I've tested these changes allow to do it. I will can write like this

%options moduleName=myGrammar;

Jison will get this option and declare generated parser with proper module name

[just-boris]

ping @zaach

[zaach]

For the syntax, I'd prefer something that resembles what the lexical grammar already uses, e.g. %options myopt1 myopt2. We could expand that to allow assignment of a value, e.g. %options myopt1=blah myopt2=foob.

[just-boris]

@zaach done. Now it consumes = symbol between key and value