Remove trailing space
Add NS_OPTIONS for bitmasks
Minor phrasing change and add bit shift operators to example
Merge pull request #60 from jlmendezbonini/bitmasks

Add section about NS_OPTIONS macro for bitmasks
Merge remote-tracking branch 'upstream/master'

* upstream/master:
  Minor phrasing change and add bit shift operators to example
  Add NS_OPTIONS for bitmasks
  Remove trailing space