- Remove old NULL kludge

Restored Makefile.am and added a test for cross-compiling in configure.ac. The LIBGCRYPT macro didn't test for the cross-compile situation.

* luaplaylist.c, README.txt: add .duration option for playlist items. Should now be possible to rewrite our m3u parser entirely in Lua :D
* m3u.c: indentation fix.

* *.lua: misc fixes.

* share/luaplaylist/youtube_homepage.lua: New lua parser script to open youtube home/browse pages. This demos the ability to return more than one item in lua playlist scripts.

* ffmpeg/demux.c: Don't change an ffmpeg demux's .flags member permanently. Fixes the "ffmpeg demuxer can't be used more that once" bug with libavformat revisions newer than 7589 (included).

* luaplaylist.c: Look for Lua scripts in the user's CONFIG_DIR"/luaplaylist" directory too. (+ fix probable compilation errors on WIN32, APPLE and BEOS)

* modules/access/http.c: When redirecting, don't include port number in URL if it's using the default port.

* src/input/input.c: Remove the access and demux part from the path string. (Fixes [20059] a bit ... even though it wasn't really broken)