Schedule the timer in the common run loop modes.

Previously, the fade out timer was being added to the default run loop
(as a side effect of +scheduledTimerWithTimeInterval:).  This caused
the timer to "freeze" while user events were being tracked (such as
while scrolling or handling touches).

Fixes #94.
Merge pull request #95 from jparise/timer-runloop

Schedule the timer in the common run loop modes.
Don't force the show/hide on the main thread, dev is the one responsible for this.
Merge and fix conflicts.
Add updated podspec.
Remove ARC build warning
Convert demo project to ARC.
Fix ARC warning in demo project.
Set podspec's requires_arc to true.
Address UITextAlignment deprecation warnings in iOS 6.
Merge pull request #100 from jparise/textalignment-ios6

Address UITextAlignment deprecation warnings in iOS 6.
Set accessibility label and element

If the SVProgressHUDMaskType doesn't allow any user interaction, the
whole view is set as the accessibility element. If the mask type is
SVProgressHUDMaskTypeNone only the hud view is set as the accessibility
element.

When showing the hud, Voice Over announces the status message.
cleanup
Merge pull request #101 from julienp/accessibility

Set accessibility label and element
Update project to recommended settings.
Merge branch 'master' of github.com:samvermette/SVProgressHUD
Ensure HUD overlayWindow is visible above other windows.

Even without creating other windows, in some cases (it depends on how iOS is displaying the windows) the HUD's overlayWindow won't be visible. The display of windows with the same level doesn't appear to be guaranteed, so we should position the HUD at a higher level to guarantee visibility.
Added an implementation of UIAppearance
Remove dealloc completely (singletons don't need one: http://stackoverflow.com/questions/5010701).
Update keyboard view finding code for iOS 6.