Add EOF parser
Add constant_function class template
Add char parser
Add copy, copy_if, move function templates
Add repeat parser template
Add one_or_more parser template
Report exception in check_parser

For ease of debugging, check_parser should show the type of the
exception if the resultant trial contains an exception.
Add raw_string parser
Merge pull request #143 from magicant/feature/parser

Implementation of raw string parser