remove confusing multiple session handling code
it doesn't actually do anything and was cruft
also, make session overriding non-default based on the mobile
JSONWP discussions
check in midway through android startup/shutdown refactor
finish making shutdown() callback-based
command timeouts should be handled centrally by appium, not by each device
when we get an error starting up an android test, make sure we kill uiautomator
so it doesn't complain next time we run a test
Merge pull request #1372 from jlipps/master

Cleanup/refactor of appium/android startup/shutdown