Added error handling/reporting for `debugger.outputfilter`.
Improved file activation for abbreviated file names in error messages.
Added reporting of socket error for initial debugger calls (Mobdebug 0.5403).
Updated OSX build script to not strip debug builds.
Updated Windows build script to enable gdb debugging.
Added margin constants and removed unused variables.
Added recalculating line number margin width after zooming (fixes #207).
Added socket.connect for compatibility with socket.core <3.0 (fixes #208).