add package.json
add bower.json
Add .aac files support

Tested with [a file](http://download.wavetlan.com/SVV/Media/HTTP/AAC/Roxio_Media_Manager/RoxioMediaManager_test4_AAC-LC_v4_Stereo_CBR_64kbps_44100Hz.aac) found on [wavetlan](http://download.wavetlan.com/SVV/Media/HTTP/http-aac.htm)
Add audio/m4a and audio/mp4 mime type tests

Should fix #149
Merge branch 'pr/162'
Merge branch 'pr/160'

Conflicts:
	howler.js
Merge branch 'pr/153'
Finish setting up npm and bower configs
Make it clear in docs that pos is in seconds
Fix calculation of audio pos/duration that would sometimes be off when using sprites
Clear the event listener when creating new HTML5 Audio node
v1.1.21
Fix typo in npm config
Merge remote-tracking branch 'origin/master'