activex: fixed type library crash (this would cause most programming language to crash), IE does not use type library and was immune to this problem

  - use ToLocale open for the .bin vcdimage file (not 100% fixed, but better then before and i don't feel like backporting utf8_open)
  - Try .bin when opening a .cue, instead of trying the filename in the .cue (it's usually wrong). 
    When the .bin filename fails, then look into the .cue file for a possible alternate name. 
  - Don't crash on non-existing cuefile's

* Update the NEWS

* backport [17752]: allow empty subtitles. These are used to wipe ephemer substitles of the screen. Used by Timed Text

There is still a lot of fixes to be backported here.

(before getopt_long gets the chance to reorder them)

Should be probably called backport [17739] but it's different
since libvlc went through significant changes in trunk.

closes #830

* Initialize all the fields in the sdp_t of out sap parser. Fixes a FreeSDP crash i was sometimes seeing on OS X.

  [17556] was supposed to contain this already, but i guess i made a mistake

- added custom events processing on main thread for plugin fullscreen window, this is similar to Cocoa [performSelectorOnMainThread]
- ShowWindow/HideWindow for plugin fullscreen window are now run on main thread as they are not thread safe and may cause crashes