Update MessageDisplayKit.podspec v0.2.2 file

Merge pull request xhzengAIB#119 from yourtion/master

Fix pod error AudioToolbox

Fix the warnings

Fix the block bug.

Update README.md

fix the error for XHPhotographyHelper weakSelf.

Update README.md

Update v0.1.5

fix the header import error for v0.1.4

update file