ensures we close any .xbt packs regardless of whether we've taken a texture from them or not - closes #10876

[WIN32] fixed: building of libdvd was broken due to using msys automake instead of mingw automake. Dunno what's the difference there and why one lib compiles with the first and another with the latter only.
Now we have both. Hope they won't interfere.

Our poll implementation does not iterate over the pollfd array properly
while setting the revents.

Cherry-picked from git.ffmpeg.org 9ac2085dbf1821b7995fe360038c1bf0f3940032

This fixes #11241

ensure that we clear the items in the login window - fixes spurious error messages about textures being cleaned up/unable to release.

added: advancedsettings.xml option <tvmultipartmatching> in order to modify the default multipart enumeration regexp

changed: renamed m_tvshowMultiPartStackRegExp to m_tvshowMultiPartEnumRegExp as it's used to enumerate - not stack - a multipart episode.

[WIN32] added scripts to download our custom fribidi lib from google code (will move to our mirror later)

Even though it's correct to check for stacked paths this is causing weird
problems with stacked archives and the media scanner. Reverting for the moment.

fixed: fps in system info was shown as Hz, even though expressing fps as hertz is correct, most people will confuse it with the refreshrate

[WIN32] changed: use msys automake instead of mingw as it includes binaries without version numbers (would be a symlink on Linux)

Signed-off-by: Joakim Plate <elupus@xbmc.org>