Bug 833913 - Part 1: s/PR_TRUE/true in nsISimpleEnumerator.idl comment.
Bug 833913 - Part 2: Make about:memory sort reporters with equal amounts by name, and update the tests to match this.
Bug 833913 - Part 3: Switch nsMemoryReporterManager to using nsTHashtable.

This makes NS_RegisterMemoryReporter() and NS_UnregisterMemoryReporter()
O(1).  Previously, they took time linear to the number of registered
reporters.