Fixed parse error reporting.

Exceptions with context information were decorated with another context information. Fixed by adding exception class parse_error.
Fixed string escaping.

It looks like using \x22 instead of \" wasn't good idea, clang tried to consume extra characters, eg. 'c' in \x22c.
Added missing generic-template.diff
Merge branch 'generic-templates' into dev
Merge branch 'dev' into fix-string-escaping
Complete fixing '"' character escaping.