BEWARE: If you have non-recompiled plugins, they WILL crash.

 - remove useless IsSubmodule (submodules have NO configuration items anyway, and any sensible UI won't show modules with no configuration)
 - free checks for NULL anyway

* modules/gui/wxwidgets: fix breakage introduced by changeset 23581 and 23579. Breaking perfectly working modules just because you don't care about them is just rude.

Add OpenPGP code, still unused as there is no download of binaries at the moment

We will need to define (and write) the files (and their location) we will use in the update system:

    * We will use a file per arch, which will be signed
    * ALL VideoLAN gpg public keys will be stored on http://download.videolan.org/pub/keys/XXXXXXXXXXXXXXXX.asc where XXXXXXXXXXXXXXXX is the long id of the key
    * Every downloadable file will be signed with gpg --sign --detach --armor

modules/macosx/prefs_widgets.m: module_GetConfig doesn't accept second arg as NULL, quickly work around that.

modules/gui/macosx/prefs*.m: Fix for module_t privatization. Feel free to test. That code is unreadable.

control/media_descriptor.c: As requested by Jacques Boileau, allow options tuning from the media_descriptor class. This is done through libvlc_media_descriptor_add_option.

Qt4 - VLM improvements... Classing for the three kind of objects, more property editing and less segfaults (though there is one I have nooo clue ).

Qt4 - Art in the playlist is collapsable with the use of a QSplitter. If you really don't like, please revert.

SET_PARAMETER is simply *wrong*. Servers are not supposed to support except for proprietary extensions (meaning we cannot use for just any random server).
Even GET_PARAMETER is hardly good, as it is not mandatory to implement either, but it is a defined way to ping (which SET_PARAMETER ain't).
In any case, the only proper way to ping a stream is RTCP feedback.
When it comes to the control session, better check OPTIONS Allow: header for GET_PARAMETER.

I really wonder how live555 can be so low-level though - smells like we are trying to be too intelligent here.

Patch by Jilles Tjoelker. Fixes crash in playlist due to negative index in playlist item array. Added boundary check to solve this.