pygments support in hgweb

[Adam Hupp]

I've modified hgweb to apply pygments syntax highlighting in the file
revision view.  It's based on this patch[0] but has the following
improvements:

 * uses an external css file instead of inline styles.
 * falls back to a plain view if pygments is not available or is disabled
 * language determined based on file extension and contents
 * supports striped line highlighting

The changes are available in this repo:

http://hupp.org/adam/hg/hg-pygments

That repository is running the changes.

One issue I ran into was an "unloaded module not callable" error
within pygments.  This was resolved by adding
mercurial.demandimport.disable() at the top of hgweb_mod.py.  That's
probably not the right solution but I'm not sure how else to handle
it.

Is there any interest in including this change in mercurial?

[0] http://www.selenic.com/pipermail/mercurial/2007-May/013207.html

-- 
Adam Hupp | http://hupp.org/adam/