Convert the xibs to Xcode 5.1 format.
The SUUpdateAlert wasn’t migrated in this commit because of the autolayout branch.
Migrate the SUUpdateAlert xibs to Xcode 5.
Finish moving all informal protocols to formal protocols.
Fix improperly-named protocols.
Updated README
Merge pull request #335 from pornel/master

Finish moving all informal protocols to formal protocols.
Merge pull request #39 from pornel/Xcode5xibs

Migrate xibs to Xcode 5
Switched SUUpdateAlert.xib to AutoLayout
Remove the left alignment on the description text.