Transactions

[naftaly]

This PR is a combination of ( Both those branches were required in order to pull it off ).

• Animation groups #275
• keyPath property animations #274

Added:

• POPTransaction. Used to run many shorthand animations together ( similar to CATransaction ).

[POPTransaction begin];

[POPTransaction setAnimationDuration:10];
obj1.pop_animator.value = 1;

[POPTransaction setAnimationDuration:3];
obj2.pop_animator.value = 5;

[POPTransaction setCompletionBlock:^(BOOL finished) {
  // do stuff after obj1 animation has run for 10 seconds and obj2 animation has run for 3.
}];

[POPTransaction commit];

• block based shorthand animations ( [NSObject pop_animateWith... ).

[NSObject pop_animateWithDuration:0.4 delay:1 options:POPAnimationOptionAutoreverse|POPAnimationOptionCurveEaseOut  animations:^() {
  // you're in a transaction here so change stuff if you want to.
  obj1.pop_animator.value = 1;
  obj2.pop_animator.value = 5;
} completion:^() {
  // do stuff ...
}];