Improve .gitignore
Use SimpleCov instead of rcov and improve Rakefile
Add offset support for Chronic::construct and improve Date, Time classes
Change :guess option so can specify which part of Span should return
Merge pull request #206 from davispuh/parser_improvements

Parser improvements (continuation)
document changes
Merge pull request #207 from davispuh/changelog

Document changes
Update HISTORY
Bump version
Release 0.10.0