peg_parser.d matches peg.js

- split out peg parser into pegparser.ts file
- added common.js and html script load support to peg.ts
- the define.parse() is called for each definition before parsing starts
- used to reset internal variables
- defn supports a <grammar>$<definition> syntax.  if <grammar>$ is not
present, the current grammar is used
- the name of a grammar is assumed to be the first entry in the
definitions structure
- multiple definitions can be added to a single parser (at the moment,
we start the parsing using only the first definition of the first
grammar)
- the peg grammar was updated to perform the results to code step
- the peg_parser.d was used to generate a peg.js, which could parse
peg_parser.d and re-generate itself