Fixed class Mine documentation.
Removed Mine.done_queueing_input, and instead directly compared Mine.queued_count with len(Mine.identifiers)
A few minor fixes for Miner.

- Made doing "for Miner.items()" multiple times work
- Handled (some: not identifier '%%') cases when would cause the miner to infinitely loop
- Changed While True: if <cond>: break to while not <cond>:
Made miner into a generator.
Minor: Changed how to install gevent to installing it from pypi, not the git repository. They've released the final version of 1.0 now, so the one i pypi has whatever was needed from 1.0rc2
Merge branch 'master', remote-tracking branch 'upstream/master'
Added max_requests. Added docstring for __init__. Had internetarchive import Mine,
and made the the main way to use it in usage.
Merge pull request #42 from fibn144/master

Made Mine a generator, other small fixes.