[PATCH] Remove references to tigris.org from website

Hi,

I've looked through the website and I propose a few administrative changes.
It's my first patch so fingers crossed I have not messed up!

In the first half of the email I have detailed a few things I'm not sure
how to handle, in the second half of the e-mail I have a formal log
message. Sorry if this makes it harder to read but I tried to make it
easier for whoever might commit this to just copy-n-paste the log message.

docs/community-guide/releasing.html
I'm not sure if it's possible to rediscover exactly which e-mail was
referenced but the following e-mail seems to fit the description quite
well:
https://mail-archives.apache.org/mod_mbox/subversion-announce/201106.mbox/%3CBANLkTi%3DhFhXwpyGKp7XOsL4j39tssD363A%40mail.gmail.com%3E

reporting-issues.html
Was Issuezilla ever archived or should that section be eliminated? I have
_not_ included this in the patch, just wanted to point out.

docs/community-guide/l10n.html
The page mentions localization mailing lists. Is there a new home for them
away from tigris.org? _Not_ included in the patch.

docs/community-guide/roles.html
I realise I'm inconsistent in the links to mailing lists by linking to
svn.haxx.se here however the mail does not exist in mail-archives.a.o. I
saw a thread from April this year suggesting to migrate also the older
archives to apache servers but until this happens there will have to links
to both sites. Or do you prefer to link everything to svn.haxx.se?

And here is the log message:
[[[
Remove references to tigris.org from website

* docs/community-guide/general.html
  Participating in the community: Changed link to issue tracker to Jira

* docs/community-guide/releasing.html
  Release numbering, Alpha and Beta: Replaced broken link to tigris.org

* docs/community-guide/roles.part.html
  How partial commit access is granted: Replaced broken link to tigris.org
]]]

Kind regards
Daniel