1.0.8-stable

This release adds two new options to filter():

1. $lower_case specifies whether you want to convert to lower case (the default), or preserve the existing case of the text.
2. $treat_underscore_as_space specifies whether you want to convert underscores to spaces (the default), or preserve underscores in the output.

Thanks @ywarnier and @jmontoyaa for these additions!