Abstracted Timer class from AnswerTimer

New class placed in jeoparpy.ui.maingame.util, to be used with clue timeouts.
End functionality and podium/AnswerTimer API have not changed.
Comment upates
Add docstring to ui.maingame.util
Clue timeouts implemented.

New setting found in jeoparpy.config.CLUE_TIMEOUT_MS. Docs not yet updated.
Clue timer now disabled if no timeout

Disabled if CLUE_TIMEOUT_MS <=0 or None, as described in config.py. Also changed default value of CLUE_TIMEOUT_MS
Clue timeout implemented for audio reading clues

Timer begins immediately following the end of the reading. For clues with an audio reading and further attached audio, the timer is not triggered; The secondary audio is played immediately following the reading.
Merge branch 'master' into feat_cluetimeout

Just small docs updates in master since the branch was created.
Docs update to v0.9.4.

Deleted dev/state_flow.png because it no longer is accurate given the new START_CLUE_TIMER state. It should be updated and replaced soon.