timecard.py: a simple timecard / clocking program.

i was inspired by a ruby program i saw on hacker news,
artem's "C.rb, A Time Clocker For Your Next Project" (available at
http://artem.posterous.com/crb-a-time-clocker-for-your-next-project).

what does it do better and why rewrite it?
basically, i wanted the ability to keep track of which project i was
and the ability to report statistics per-project.

caveats:
projects cannot have a dash in their name because of the way dates
are parsed. this is a known bug and will hopefully be addressed.

usage spec: tc clock in or out of project tc ? am i clocked in? tc --conky conky-friendly version of '?' command tc --time basic statistics on time spent tc --report <week|month|year> report statistics based on time period tc --projects list projects worked on tc -h prints usage tc --log show timecard log