Fixed an issue with the Project tree when project and app directories are the same.
Updated project tree workaround on OSX as it's not needed with wx 2.9.5+ (ref #89).
Fixed default perspective to include Stack and Watch windows (ref #103).
Rearranged saving settings to properly save on OSX (helps #89).
Fixed an issue with Enter used to select an item in project dropdown (ref #89).

On Windows multiple COMBOBOX_SELECTED events are sent when Enter is used,
which may lead to run-time errors. Disabled processing of multiple copies
of the same event.
Changed auto-recovery mark to be only applied after text changes.
Optimized project switching and added notebook freezing where possible (ref #89).
Added hiding floating windows and removed excessive manager updates to reduce flicker.
Revert "Updated editor handlers to improve performance on OSX with wx2.9.5".

The revert is needed as wx2.9.5 doesn't properly refresh status bar with
this change (on OSX, which the original improvement targeted).
Added migration of configuration file on Windows (helps #89).
Reduced flicker in the project tree when a file is opened (ref #89).
Updated error messages from loading configuration files.
Made application name an optional parameter; reorganized on-exit workarounds.
Forced floating of Stack and Watch windows by default (ref #89).