By default set multi_selection to false.

More consistent this way and possible to fallback to html4 right out of
the box.
By default look for Flash/Silverlight shims under js/ folder.
settings object should be defined before we pass a reference to it to uploader.settings.

TODO: Some unit tests in this part...
No need to have assignment to the runtime property down there.

Now that the settings are generated above.
UI: Detach destruction on plupload.INIT_ERROR to avoid operations on destroyed object.
Make original chunking format default again.

After some thinking I realized that all the benefits of new format can
be implemeted with the old one as well if rewrited differenetly. And
since some rewrite is required anyway, introducing the new is not
exactly useful.
Check if max_file_size is set before trying to filter by it.
Add more caps that might influence runtime selection.
Test if fileInput is not false before triggering Refresh on it.
url and browse_button are required options, trigger plupload.INIT_ERROR if either is not set.
Do not null internal files and events registries on destroy, assign defaults instead.
multi_selection should be true by default, setting it to false was wrong.

In general it is not exactly a good idea to switch original logic like
that.
Consider Plupload settings as required features only if required_features is set to true.

Otherwise consider them optional.
UI: use sprintf() for replacements. Combine and cleanup Error handlers.
Handlers passed in 'preinit' and 'init' properties should be attached no matter what.
Build/Tests: Use source version of moxie in tests.
Tests: Plupload static methods.
Tests: Uploader initialization.
Merge updates on a draft branch.