Fix mistake in evaluation of array literal expression

Array literal expressions expand to calls to +[NSArray
arrayWithObjects:count:], not to +[NSArray arrayWithObjects:].
(http://clang.llvm.org/docs/ObjectiveCLiterals.html)
Fixing the example to use the right constructor.
Merge pull request #108 from nataliq/object_literals_fixes

Fix mistake in evaluation of array literal expression
Adding article on Empathy
[Issue #107] Adding update about iOS 7 use of instancetype for UIAppearance
Fixing link markup
Adding NSURL article
Minor copy editing