Scratchpad and Rules

This release of howm has the following:

Bugfixes:

• Fixed client_to_ws not looking at the correct workspace.
• Fixed strange behaviour on the last workspace.
• Fixed a bug whereby cutting wouldn't cut all clients, so some would get "lost".
• Fixed kill_client not behaving well with multiple workspaces and not correctly restoring focus.

Features:

• Added a make rule to check the style of the code (make check).
• Added rules so that clients can be sent to certain workspaces and have properties set about them when they start.
• Added a scratchpad to keep a window out of view, but easy to retrieve.