First cut, not finished, for comments/feedback.
First batch of package globals gone.
More package globals nuked.
Better method to handle commands.
Move events into MesosMaster struct.  In prep for handling events better.
Piece out offer events.
More cruft removal, test task of /bin/true.
More event driven.  Far from perfect.
Async create of task
Fixup task state String()
Nuke errant comment.
Whoops, forgot to use user from flags. :)
Merge branch 'master' into async-state-machine
Fixup more things.

 - Move simplistic taskstore into its own file
 - Parcel out task updates into a new channel
 - Create a new type (TaskStateUpdate) to communicate on this channel
 - Hang 'Ack()' off this type.
 - Have a human readable version be generated via 'String()'
 - Nuke test task, use curl(1) to test instead. :)
 - Fix various bugs
Move MesosMaster -> Driver

This is then referenced as 'mesos.Driver', instead of 'mesos.MesosMaster', more golike.
More cleanup
Auto start driver with simple New().
Hide mesosTask from exports/etc.
Hide uuid for now.
Tweaks to naming and logging