ThumbJam update brings iOS8 compatability just in time

Here's what's new in ThumbJam:

• updated to latest Audiobus SDK, and improved IAA support
• fixed iOS8 compatibility issues
• multi-instrument presets are now saved explicitly
• fixed monophonic mode issues with split screen
• fixed sustain and sustain lock issue when recording loops
• fixed crash on iTunes song selection and playing
• added option (defaulting to off) to toggle visibility of All Off button
• centered pan via midi (CC10) allows for default panning of instruments
• fixed issue with monitoring when in Audiobus output slot