fix parsing language for code snippet and indent level on code blocks in lists
Merge branch 'master' into 0.2.0
Merge branch 'master' into 0.2.0

Conflicts:
	README.md
Fix #23; support strptime format strings
Extract common code between date/time filters
Merge branch 'master' into 0.2.0

Conflicts:
	lib/active_interaction/filters/date_time_filter.rb
	lib/active_interaction/filters/time_filter.rb
Fix #20; support transactions
Move require out of method

There's no reason to call it every time. I originally had it like that
to make it easier to test. However, I'm happy with the rest of the AR
tests. I don't think we need to test that require gets called.
Fix #24; strip string values
Re #32; remove return_nil
Re #32; remove bad_value

This required changing how the AbstractDateTimeFilter worked. Now
instead of passing in a "klass" parameter, I shove the class into the
options.
Use a case statement for the time filter

This keeps all the filters consistent.
Merge branch '0.2.0'
Update documentation with transaction stuff
Update changelog
Version bump to 0.2.0