Update README and podspec

Bumped version to 3.6.4 (readme)

Bumped version to 3.6.3 (podspec)

Bumped version to 3.6.2 (readme)

Changed version in README

Update README.md

Bumped version in README

Bumped version in README for 3.4.3

Merge branch 'master' of github.com:TheLevelUp/ZXingObjC

Update ZXingObjC.podspec

- bumped patch version