Refactor gemspec.
Handle errors.
Add context spec.
Specify logger namespace.
Add multi logger spec.
Filter spec at simplecov.
Add handler group pattern at simplecov.
Change register to include.
Add guard & growl gem to development dependency.
Add yard gem to development dependency.
Split core extension.
Add string extension spec.
Add extension group at simplecov.
Add notifies & stores spec.
Refactor completion function.
Add user stream spec.
Delete interface methods.
Add handlers spec.