web: rm mibbit.html which doesn't work anymore.

Mibbit has been banned on many IRC networks beccause it makes it
difficult to ban people and makes it easy to circumvent bans. It hasn't
worked for OFTC for quite a long time and the link to mibbit.html has
been removed months ago from the website. This commit merely removes the
leftover file.

Note that OFTC has a its own webchat own but I haven't checked it
(yet?).

git-svn-id: https://svn.code.sf.net/p/mingw-w64/code@6621 4407c894-4637-0410-b4f5-ada5f102cad1
web: display at most 30 related projects but always show friend projects.

The list of related projects has been getting fairly long, almost a
hundred. This splits the list into two: friend projects (wine, ros, cygwin)
and every other. The others are again split into categories: package
providers, compilers/IDEs/tools and users.

The friend projects are always shown on the main page. For the others, 30
random ones are shown (all categories merged).

There is also a new webpage with the full list. It's currently a bit bare
but the idea is to have some more space to write descriptions and so on.


git-svn-id: https://svn.code.sf.net/p/mingw-w64/code@6622 4407c894-4637-0410-b4f5-ada5f102cad1
web: rename the "Downloads" page into "Downloads and Installation".

Users either search for "mingw-w64 download" or "mingw-w64 install(ation)"
on search engines. Accomodate for that by putting both keywords on the
page.

git-svn-id: https://svn.code.sf.net/p/mingw-w64/code@6623 4407c894-4637-0410-b4f5-ada5f102cad1
web: reword the "threading model" description as yes/no to C*11 threading.

"POSIX threading model" is confusing. It's an implementation detail while
the real question is whether C11 and C++11 threading support is available
or not. Therefore, just say that.
Also add a note about the requirement on winpthreads.

git-svn-id: https://svn.code.sf.net/p/mingw-w64/code@6624 4407c894-4637-0410-b4f5-ada5f102cad1
web: missing update to the css.

git-svn-id: https://svn.code.sf.net/p/mingw-w64/code@6625 4407c894-4637-0410-b4f5-ada5f102cad1
web: update download links and wording related to C*11 threading.

git-svn-id: https://svn.code.sf.net/p/mingw-w64/code@6626 4407c894-4637-0410-b4f5-ada5f102cad1
web: remove google-analytics, to which nobody has access to.

git-svn-id: https://svn.code.sf.net/p/mingw-w64/code@6627 4407c894-4637-0410-b4f5-ada5f102cad1