Merge pull request #559 from apathyboy/command_crashes

Control the lifetime of the bp::object that commands are extracted from ...
Handlers are now wrapped in a try-catch

Handler calls are now wrapped in a try-catch to ensure that all handlers receive their callback in the case of an error.
Merge pull request #560 from rcythr/develop

Handlers are now wrapped in a try-catch
fix for linux compiling
Merge pull request #564 from J-N/develop

fix for linux compiling
Merge remote-tracking branch 'anh/develop' into scripting_cleanup