Added support for plugin debug messages and better error reporting
when something goes wrong during start up of SLPlugin.
Also added more debug output regarding general plugin messages
as well as debug output related to AIFilePicker.
This commit contains all changes to indra/llplugin.
Since there were no differences at all between Singularity and
imprudence before this patch, it's a perfect port.
Fixed by updating indra/cmake/WebKitLibPlugin.cmake with
version from imprudence.
This commit also contains removal of execute permissions
of source files and configure files, sorry...
