Merge pull request #37 from magicant/feature/delete-parser

Remove old parser implementation
Merge pull request #38 from magicant/feature/new-parser

New char filter/parser
Use std::addressof in Maybe::operator->

Use of operator& is not safe because it may be overloaded.
Merge pull request #39 from magicant/fix/maybe

Use std::addressof in Maybe::operator->
Add Repeat class template
Add StringParser class alias
Declare move constructor & assigner of Parser

A user-declared destructor requires the move constructor and assignment
operator to be user-declared as well.
Add RawStringParser class