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.
Add back fixes that were in Singularity (in indra/media_plugins) but not
in imprudence.
Also:
Add "shutdown" plugin message and terminate file picker plugins cleanly.
The DSO (libbasic_plugin_filepicker.so) now tells the child process /
plugin loader (SLPlugin) to terminate (using the 'shutdown' message),
and AIFilePicker::finish_impl destroys the plugin object on the viewer
side when it's ... finished thus.
Also added a large comment that gives an overview of all classes
involved on the viewer side.
Additional fixes for filepicker.
Plugin refactor bug fix: mDeleteMe was uninitialized in AIPluginFilePicker.
This commit deletes all indra/media_plugins and copied one-on-one
the indra/plugins directory from my (imprudence) statemachine branch
(which contains the AIFilePicker patch).
git shows this as a lot of 'renamed' files because originally it
was a rename. However, there are a lot of changes as well: it's both
an upgrade to a newer plugin system (changes by LL) as well as an
upgrade to my refactored plugin system with a file picker as plugin.
Since this commit is a one-on-one copy, it disregards any changes
that were in Singularity and not in imprudence in indra/media_plugins
however. I will add those back in the next commit.
