Merge pull request xmartlabs#311 from xmartlabs/version/7.0.0

new 7.0.0 version

release version 6.0.0

release 5.1.0

Merge pull request xmartlabs#148 from xmartlabs/version_5_0_0

Xcode 7.3 support. Now Swift 2.2 is required.

Merge pull request xmartlabs#144 from xmartlabs/4_0_2

version 4.0.2

4.0.1 pod version.

Merge pull request xmartlabs#112 from xmartlabs/swift

migration to Swift language

minor fix

fix xmartlabs#59

Back minimum system version to 7.0.

clean up code.