Return reports from failed parsing in repeat

It looks more useful to keep all reports in the result of a repeat. The
intention is to distinguish recoverable and unrecoverable failures. Only
unrecoverable failures should report errors. Recoverable failures are
ordinarily recovered so the reports are likely to be ignored anyway.
Add word component parser

Only raw strings are supported now.
Add word parser
Add type_tag_set class template
Add token parser
Merge pull request #149 from magicant/feature/parser

Implementation of token parser