Spaces in project names

Hi!

I have some projects that have space character in their name and this breaks the syncing of tasks. Tasks get generated but they are not found on the re-syncing so they are regenerated.

I investigated a bit and the problem can be fixed by changing the regular expression here: https://github.com/seattlerb/omnifocus/blob/master/lib/omnifocus.rb#L123

I'm too weak with regular expressions but will get it done if a patch is OK for you. I use only Github and Pivotal Tracker integrations so I don't know if there might be some integrations that would be affected badly by this change (adding space as a supported character in the project name).

Thanks in advance!