Move the main script load code to FCKScriptLoader

[FredCK]

The FCKScriptLoader object simplify the loading of specific components from the editor code library, and guaranties all dependencies are loaded in the correct order.

There are still many entries missing in the FCKScriptLoader scripts list. We should complete it.

Once complete, we should be able to change the fckeditor.html file, removing all "LoadScript" entries with a single call like:

FCKScriptLoader.Load( 'FCKeditor' ) ;

The 'FCKeditor' entry, is a special script name that identifies the main editor code (it doesn't have a relative script file).

We should also use the FCKScriptLoader to make it automatically generate the list of files to be placed in the _packager.xml file.