media: reply with 488 Not Acceptable Here when INVITE from self is received
Fix #237: HTML escaping not removed from URL

When you copy & paste (or drag & drop) an URL that includes an
escapeable character, then Pidgin will escape the URL when creating the
HREF attribute. I.e.

   http://test/?a=1&b=1

will result in the following HTML received by SIPE:

   <a href="http://test/?a=1&amp;b=1">http://test/?a=1&amp;b=1</a>

As we parse the HTML to reduce it to plain text, we need to un-escape
the HREF attribute to get the correct URL text to send to the other
side.

NOTE: At the time of this writing Pidgin has a bug. If you enter by hand
the following URL

   http://test/?a=1&amp;b=1

SIPE will receive the following HTML

   <A HREF="http://test/?a=1&amp;b=1">http://test/?a=1&amp;amp;b=1</A>

i.e. the URL has not been correctly escaped. As SIPE will unescape the
HREF attribute, we will send to the other side

   http://test/?a=1&b=1
configure: add .xz tarball

The .xz tarball is smaller than the .bz2 one.
Fix #238: False "not delivered" in conference

When Lync Archiving option is enabled, then the IMDN (Instant Message
Delivery Notification) XML for conference messages contains "recipient"
nodes also in the case of successful delivery, with a status code of 200.

sipe_process_imdn() now parses the "status" node and only generates a
"message not delivered" error if that node is missing or the error code
is greater or equal to 300.
l10n: sync translations with transifex.net (pt)