add category for imageView's highlighted state
Merge pull request #646 from Whirlwind/master

add category for imageView's highlighted state
Update projects to recommended settings
Improve logging and fix arm64 warnings when printing integers with %d
Merge pull request #720 from rivera-ernesto/update_projects

Update projects to Xcode recommended settings
Merge pull request #721 from rivera-ernesto/improve_logging

Improve logging and fix arm64 warnings when printing integers with %d
It's generally a bad idea to remove items from a container while iterating through it. And fix the thread safe issue.
Merge pull request #727 from kejinlu/master

It's generally a bad idea to remove items from a container while iterating through it.
The ioQueue is "SERIAL" ，so "dispatch_barrier_async" is not needed.
Merge pull request #728 from kejinlu/master

The ioQueue is "SERIAL" ，so "dispatch_barrier_async" is not needed.