Expose lexing functions for XMLDoc extension
Merge pull request #45 from dungpa/xmldoc

Expose lexing functions for XMLDoc extension
Fix typo (s/PsuedoValue/PseudoValue/).
Remove duplicate declaration in signature file.
Fix comment.
Merge pull request #47 from jskripsky/master

Minor fixes (typo, duplicate declaration, wrong comment).
Merge branch 'master' of https://github.com/fsharp/FSharp.Compiler.Service