Compile with latest snap.
Address all compiler warnings.
Initial travis-ci integration.
Qualify Control.Exception imports.

In older versions of base, Prelude exported "catch". The qualified
lets us avoid warnings with older or newer versions of base.
Replace missing import of storable-tuple module.
More conservative bearing controller.
Relax vector dependency in generated packages.
Relaxed dependency constraints.
Improved path handling with the filemanip package.

Finding packages and message files should be more robust.
Added all Turtle example variations.
Experiment with optparse-applicative.

Help formatting is too limited.
Add an unregister roshask sub-command.

This command calls ghc-pkg unregister on every package whose name
begins "ROS-" after confirming the user's intent. This is helpful when
upgrading roshask.

Reinstated manual option parsing and help text.
Don't re-generate already registered packages.
Massive code base reorganization.

Moved everything used only by the roshask executable into
src/executable, and stripped off the module path prefix
(i.e. Ros.Core.Msg).

Simplifed the directory structure underneath Ros.

Renamed "Core" to "Internal" everywhere. The word "Core" was
unfortunate as it suggested a relationship with roscore.