Move rspec config into spec_helper
Fix RSpec to_not raise_error
Remove debug log
Reformat the readme to 80 columns
Move version to its own file
Refactor DateTime delegating to core ruby when poassible
Add validation for wrong precision matching
Add invalid datetime test
Add sign to datetimes
Add tests to cover negative years
Refactor delegated methods tests
Update changes list for 0.5
Add differences with core classes
Refactor DateTime tests
Fix dealing with time components when no date component
Fix documentation
Add DateTime#to_a