Don't update the same sr multiple times
Add MIT license
Reduce number of queries to Log table
Subreddit/condition init: refactor and optimize
process_messages: Allow bot owner to trigger updates
process_messages: Take "sleep" command from owner

If the user defined as the bot's owner in the cfg file sends a
message with the subject "sleep" (body text doesn't matter), the
bot will sleep for 10 seconds. This is useful if a ^C is needed
for some reason, and this replaces having it sleep after every
10th run.
Reports: check based on time, not number of runs

This adds a new cfg variable 'reports_check_period_mins', which
defines how many minutes there should be between checks of the reports
queue.
Standard conditions: handle updates properly

At the start of every pass, a check will now be done to see if the
standard conditions in the database have been updated. If they have,
all conditions are reinitialized.
get_enabled_subreddits: don't edit rows
Database: don't expire rows on commit
update_from_wiki: return whether update succeeded
includes-word: improve matching at string edges
check_condition_valid: validate modifiers
build_multireddit_groups: increase cutoff to 4700 chars
Perform full subreddit update if sr not in sr_dict is updated
Error message: improve formatting, add links
process_messages: Improve ordering of actions

This goes through all the new messages and "collects" all of the
actions that were requested first, then performs them afterwards
in the order of accepting invites, updating from wikis, and finally
sleeping. This reduces errors, especially since messages are processed
in the opposite order that they were received in.