Make #until works correctly with Date objects

Closes #118
1.9.2 fix
Fix for UTC in schedule methods based on TimeUtil.now

Closes #115
Merge branch 'master' of github.com:seejohnrun/ice_cube

Conflicts:
	spec/examples/regression_spec.rb
Bump version to 0.9.2
Add avit to collabs
Bump version to 0.9.3.dev
Add failing example for issue #115
Fix schedule spec to run in isolation

Should not depend on ActiveSupport, and module inclusion not working.
Apply the correct time zone when using ActiveSupport

Fixes #115
Merge pull request #125 from avit/issues/115-time-zone-issues

Apply correct time zone and offset to occurrences based on start_time.

Fixes #115.
Match start_time subsecs when finding occurrences

Fixes #89
Satisfy bundler with rake development dependency
Merge pull request #128 from avit/issues/120-duration

Make duration dependent on end_time
Make duration dependent on end_time

* schedule.end_time attribute controls duration.
* preference is given to :end_time over :duration for initializing.
* to_ical outputs only DTEND instead of DURATION.
* to_hash outputs only :end_time.

Issue #120
Duration should never be nil, default to zero
Ensure correct dates for different kinds of Time

Refactored & tightened specs for Schedule#occurs_on? edge cases.

Fixes #57 and #95.
Clean up specs
Clean up specs
Rules should start with uses = 0, not nil