external display mirror mode is now default

- also cleaned up ofxiPhoneAppDelegate up a little bit,
  - cleaned up formatting.
  - including ofxiPhoneViewController class reference in the
ofxiPhoneAppDelegate implementation file.
  - adjusted iosCustomSizeExample to include a reference to
ofxiPhoneViewController
Merge pull request #2200 from julapy/ios-mirror-mode-by-default

ios external display mirror mode is now default
ofAppGLFWWindow: adds multimonitor fullscreen for linux, related to issue #2195
Merge branch 'develop' of github.com:openframeworks/openFrameworks into develop
Merge branch 'develop' of github.com:openframeworks/openFrameworks into bugfix-glfw-fixes
bugfix glfw alt/ctrl/shift/super keys now correctly parsed - allows for ofGetKeyPressed(OF_KEY_LEFT_ALT) as well. closes #2197