Support HsRegexp::MULTILINE.
Support HsRegexp::IGNORECASE.
Code refinement.
Code refinement.
Add documentation.
Modify handling of flag argument of HsRegexp#initialize.
Support instance methods of Regexp.
Merge branch 'support_ignorecase'
Bug fix.

Why did I remove this line??
Bug fix of '*' handling.

This is the reason why I removed '*ep->reginput == nextch' once.