Upgrade all the example XIBs to Xcode 5.1.

- They now require Xcode 5.1 to be used.
Add secure text field to text field example.
Merge remote-tracking branch 'upstream/master' into xcode-5.1-all-the-xibs

Conflicts:
	Examples/BTRTextField/TextFieldDemo/TextFieldDemo/en.lproj/MainMenu.xib
Merge pull request #64 from rastersize/xcode-5.1-all-the-xibs

Xcode 5.1 all the XIBs