Minor bug fix

#20 Fix for ios silent mode

Thanks @gonshi .

Hotfix 1.0.7

• Fix wrong conditional branching

Thanks @ayamada.

Minor bug fix

• Fix: check volume upper & lower limit
• Suppress error on IE without console
• Suppress warning on chrome

Thanks! @thammin / @ayamada.

This release include improvements documents and develop environment.

Supports PC officially

• Added: PC browser support
• Added: test case for both PC & mobile
• Added: console.trace() on Logger method if enable
• Added: logo
• Fixed: fire ended event in using WebAudio on iOS6
• Fixed: some bugs