The plugins cache now contains plugins file path relative to the base
plugins directory (the directory that contains plugins.dat). The cache
can hence be generated from a different absolute directory than the one
it is later installed to.

For native or emulated native builds, this enables build-time cache
generation.

Note however that the relative paths are different in the build tree
(modules/*/.libs/lib*_plugin.*) and in standard installation
(plugins/*/lib*_plugin.*). The cache cannot be copied from the build
tree to the installation directory.

This ensures that the vlc_entry__main prototype matches.

This is more flexible and extensible.

This avoids going through the linked list of modules. This is fine so
long as the module structure is indeed not in the list.

This should ease later implementation of proper error handling.

Again, this should help fix leaks in error paths.

macosx: use an updated API to set the behavior of menu bar and Dock in fullscreen mode on 10.6&later

this allows the user to access the Dock while in fullscreen mode in contrast to the previous implementation. behavior on 10.5 did not change.

Modules are created at initialization and destroyed at exit (after all
VLC threads are terminated) There is no need to count references.