Add basic benchmark tests
Merge pull request #48 from ericf/master

Pass `Intl` into the module factory
Merge pull request #46 from ericf/benchmark

Add basic benchmark tests
Merge branch 'master' into perf
Update tests for new api
Update to fix errors raised from tests.

Add throw if Intl is undefined or null.
Ensure pattern exists before calling _buildFormatPattern.
Add in logic for plural offsets.
Add default value for patterns that do not consist of a format function.
Add cases for custom and undefined types.
Add NumberPart object as it was missing.
Add offset to PluralPart function.
Remove offset logic and NumberPart. Remove custom type case.
Merge branch 'perf' of github.com:ericf/intl-messageformat into perf
Ensure parse returns an array if it is a string.
Merge branch 'perf' of github.com:ericf/intl-messageformat into perf
Update tests
Tweak error messages, fix jshint warns, and validate locale structure
Clean-up tests, remove commented out tests and use better error checking