Some nice fixes and subtle changes

This is quite a small update as RL has taken over. The following bug fixes have been made:

• Fixed a workspace off by one initialisation error.
• Fixed some stylistic issues.

The following (small) features have been added:

• Howm will now check for the env variable HOWM_SOCK when it creates it socket.
• Howm no responds to cottage with IPC_ERR_NO_CONFIG if an attempt is made to change an unknown config option.
• Use a default config path if one isn't supplied.
• Added the --version option.
• Some doc improvements.

I'll update the developer docs now. :-)