Fix html_inline to work with Python 2.6.
Fix html_inline to work with Python 2.6.

Prior to this, the |flags| parameter of |re.sub| was being used, but
this didn't get added until Python 2.7. Instead, compile all regexes
that require this flag; passing flags to |re.compile| has been
supported much longer.

BUG=none

Review URL: https://codereview.chromium.org/12317096
camny125/grit-i18n,imuse2012/grit-i18n,camny125/grit-i18n,imuse2012/grit-i18n