ofxiOSSoundPlayer as default iOS player.

- removed ofxOpenALSoundPlayer and SoundEngine.
- added ofxiOSSoundPlayer and AVSoundPlayer
- updated iOS soundPlayerExample to demonstrate how both
ofxiOSSoundPlayer and AVSoundPlayer can be used within an OF app.
ofxiOSSoundPlayer as default iOS player.

- removed ofxOpenALSoundPlayer and SoundEngine.
- added ofxiOSSoundPlayer and AVSoundPlayer
- updated iOS soundPlayerExample to demonstrate how both
ofxiOSSoundPlayer and AVSoundPlayer can be used within an OF app.
updated example with different file formats.
creates missing directories when saving any files. closes #460.
changed synth.m4a to synth.mp3
removed unused orientation defines.
Merge pull request #2138 from julapy/ios-remove-unused-orientation-defines

removed unused ios orientation defines
ofBaseApp: move event (un)register to ofAppRunner for compatibility with old projects
Merge branch 'develop' of github.com:openframeworks/openFrameworks into develop
merged.
Revert "removed unused orientation defines."

This reverts commit 26bf861c9770d3c861d24bf5b390db9010b260bc.
Merge pull request #2127 from julapy/ofxiOSSoundPlayer

ofxiOSSoundPlayer as default iOS player.
Merge branch 'develop' of github.com:openframeworks/openFrameworks into fix/missing-directories
added bool return to createEnclosingDirectory
Merge pull request #2135 from kylemcdonald/fix/missing-directories

creates missing directories when saving files
Merge branch 'develop' of https://github.com/openframeworks/openFrameworks into develop
Merge pull request #2139 from julapy/undo-ios-remove-unused-orientation-defines

undo removing orientation defines.