web: reorder download page

Per my mail on the devel list from 2013-10-30, this change moves
the static builds further up in the download page and cleans up
the lists, in order to make it easier for users to discover the
downloads. Almost like a "Download here" button many users are
looking for.

Many casual users will be scared by the thought of having to compile
software, and when we send them to the download page, it's often
not apparent that the static builds work just as well.

The packages for Linux distributions have been moved down since
they contain older versions. Especially for Ubuntu, I added a
note about it being stuck at 0.10, which new users often don't
realize.

I also added links to the OS X package managers that enable users
to install ffmpeg directly.

For power users, the source code access is still there. Someone
willing to get the source will immediately see the git command.
I also changed the "people are not afraid to use them" to a more
direct statement.

Finally, a link to the wiki has been added, to point people to our
compilation guides, which are well maintained and a good reference.
web: move RSS generation to a seperate shell script

Easier to read.

Signed-off-by: Timothy Gu <timothygu99@gmail.com>
Reviewed-by: Stefano Sabatini <stefasab@gmail.com>
web/Makefile/rss: parse news archive for RSS too

Signed-off-by: Timothy Gu <timothygu99@gmail.com>
Reviewed-by: Stefano Sabatini <stefasab@gmail.com>
web/default.css: sync with ffmpeg

Signed-off-by: Timothy Gu <timothygu99@gmail.com>
Reviewed-by: Stefano Sabatini <stefasab@gmail.com>
web/documentation: add links to Git how-to and FATE doc

Signed-off-by: Timothy Gu <timothygu99@gmail.com>
Reviewed-by: Stefano Sabatini <stefasab@gmail.com>
web/projects: update FFmpegYAG url

As requested by project author.
web/security: add CVEs for 0.10.9 and 2.1

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
Revert "web: move RSS generation to a seperate shell script"

This reverts commit f4c4145a82d69a24292df4c02b8b8ebe59c4884f.

Execution of scripts from the git checkout during make is not
supported currently. The Makefile is subject to security checks
on the server, these do not extend to external scripts.
It seems none of the root admins had time until now to extend
these security checks to external scripts and noone else volunteered
to fix them either (which isnt that trivial as the checks are shared
between several projects)

Thus to restore the automated website build on push, this commit
is reverted
Better solutions welcome, patches welcome, but dont break the
website build please, also if you do break it, revert, dont
just leave it assuming someone else will fix it.
web: Remove outdated banners

Prevent them from being shown again after a year has passed.
web: add ffmpeg 2.0.3
web: move 2.0 branch to old releases as it does no longer have a dedicated maintainer