Remove too early instantiation of contentView.

This caused the contentView to be already instantiated in the awakeFromNib or init. We want to defer the creation as much as possible so that we can also consider contentInset of the underlying scroll view in the bounds of the content view
Added method to get current status of "draw debug frames"
Removed defunct debugFrames property on content view
Added method to get the current value of debug frame drawing from layout frames.
optimization to only call relayoutText on setting text  if there is a previous layout frame
Changed setFrame to only check for different size

Changing the frame origin should not trigger a re-layout
Merge branch 'master' of github.com:Cocoanetics/DTCoreText

Conflicts:
	Core/Source/DTAttributedTextContentView.m
fixed color problem on MacUnitTest
Implemented #ifdefs for OS_OBJECT_USE_OBJC

from iOS 6 and OSX 10.8 GCD objects (like semaphores) use ARC, this compiler flag adjusts the code based on whether or not the current minimum OS supports it
Fixed deprecated truncation constants

as of iOS 6.0 they have different names. There is a new function to convert to eliminate build warnings
Updated podspec for 1.2.0
Added links to Changelog articles to Read Me
Setting of content size missing
hide functions using UIKit stuff for building on Mac
Added unit test for CSS merging #280
fix for unit test to work on iOS and Mac
CurrentTest for stylesheet merging problem
Eliminate excess whitesapce above labels & fix middle/tail truncation mixup

Change-Id: Iee17956bcceebb887b2dd9b19876a1515199da62