compatible with SDK6
fix the wrong measured height for SDK6+iOS7
make content inset work.
fixed the contentSize issue in iOS7
resolveClassMethod: is wrong

use respondsToSelector: to to check at runtime if a class method exists
or not
fix measureHeight method in iOS 7
use __weak when possible
Update HPGrowingTextView.podspec
Moved call to growingTextViewDidChange out of 'refreshHeight'
Merge branch 'master' of https://github.com/GlareCH/GrowingTextView
Merge branch 'LightMail' of https://github.com/qiduo/GrowingTextView

Conflicts:
	class/HPGrowingTextView.m
Merge branch 'master' of https://github.com/seenickcode/GrowingTextView
iOS 8 fix
scroll to caret without animation on iOS7.
fix the maxNumber line is shaking up and down.