Preliminary controller and error instrumentation for rails 4 beta
RUBY-1044 Some changes to get unit tests passing under Ruby 2.0

Apparently the new Regexp engine is busted when it comes to (?i: )
syntax.  Also new minitest hates if you subtract times from integers.
RUBY-1044 Fix mocha Ruby 2.0 incompatibility
Fix flakiness in the Resque instrumentation test exposed by running with Ruby 2.0
RUBY-1045 Abide by the overridden class_name passed
Fix two bugs in Cross Application Tracing
Read the X-NewRelic-Transaction header in a more-flexible (Rack-compatible) way
Cast the two timings in returned CAT appdata to floats