Refactor: move transaction-local stats hash to the, uh, Transaction.
Refactor: remove unused scope param to trace_execution_scope_footer
Refactor: use same end time for all metrics recorded during txn finish
RUBY-1109 - Remove messages from exceptions in high security mode

Exception messages are replaced entirely rather than being scrubbed with the
sql obfuscator. The test of the previous functionality was changed to reflect
the new behavior, and a test exception class was introduced as Exception is not
representative of the type of error this feature is designed to handle.
RUBY-1109 - Exceptions are whitelisted if their ancestors are whitelisted
RUBY-1109 - Refactor constantize out of whitelisted?
RUBY-1109 - Refactor constantize
RUBY-1109 - Truthy and falsy test helpers

Test helpers to mimic be_true and be_false functionality. Methods that return
anything other than nil or false are truthy, and methods that return nil or
false are falsy.
RUBY-1109 - Comments, memoization, default message and simple refactor.

* Comment default settings with examples.
* Memoize whitelist of constants as it won't change and it's expensive.
* Use a default message to identify New Relic as the source of missing exception
  messages.
* Refactor blank whitelist return to the next line for clarity.
* Change message stripping to enable with the strip_exception_message setting.
* Reword message stripping comment as messages are replaced entirely rather than
  obfuscated.
* Fix spelling errors.
RUBY-1109 - Move constant parsing to config manager, combine config, refactor

The constant parsing is now handled in the configuration manager to prevent the
string from being parsed for each noticed error.

Configuration for the strip_exception_messages feature is now a hash with keys
'enabled' and 'whitelist', where the whitelist is a comma separated string of
exceptions that allow messages.

When the whitelist contains an undefined constant a warning is written to the
log with the constant name.
RUBY-1109 - Document whitelist in the changelog.
Merge branch 'RUBY-1109' into dev

Conflicts:
	CHANGELOG
RUBY-1096 Add debug logging for sampling rate of request sampler
Merge pull request #55 from newrelic/move-stats-to-transaction

Attach transaction-local stats to Transaction, nix a thread-local
RUBY-1096 Add supportability metrics for RequestSampler
RUBY-1123 Fix Sequel instrumentation for older versions

Checks for versions older than 3.37.0, which is the version which
the extensions and plugins system API was added in its current form.

Logs a message for older versions.
RUBY-1123 Fix the minimum version number in the log message.
RUBY-1123 Add links to the issue and ticket to the multiverse test for reference
RUBY-1123 Guard against Sequel::MAJOR being undefined

Sequel::MAJOR was added in 2.10.0, so add that to the multiverse
tests and guard against it being undefined. (props to Ben for
spotting this)
Merge pull request #67 from newrelic/RUBY-1123

RUBY-1123 Fix Sequel instrumentation for older versions