Added get_sleep_time().
Allow MidiFiles to play without real delay

This feature is useful in cases where you just need to parse
midi file with calculated timestamps for each event.
Merge pull request #16 from trushkin/develop

Allow MidiFiles to play without real delay
Modified sleep=True patch a bit and documented it.
Updated changelog.
The source code section was included twice in readme.
Copied new version of run_tests.py from dbfread.
Updated copyright in docs.
Updated description field in docs config.
Documentation can now be built with "python setup.py docs".
Documented how to build documentation. Also changed some formatting in readme.
Updated readme.
Fixed broken formatting in readme.
Added MidiFile.__iter__() and removed obsolete sleep argument to play().
Updated changelog.
Moved midi_files.rst a step up in the documentation.
Added MidiFile example to readme and moved midi_files.rst further up.
MidiFile, MidiTrack and MetaMessage are now available in the top level module.
Moved MIDI file classes and functions to higher level modules.
Updated changelog.