Make constant containing default CSS rules public
Extend sample to show how to display themed dialogs

Displaying a themed ChangeLog dialog is as easy as passing a
themed context instance and matching CSS rules to the
constructor.
Add Greek translation
Update list of contributors
Change minSdkVersion of the library to 4
Add Spanish translation

Added translations for the library and sample to Spanish language.
Update list of contributors
Remove references to strings in the library project
Update projects to use Gradle
Add Polish translation
Add Russian translation
Make it easier to read external change log files

This change breaks getLog() apart to make it easy for subclasses to read
change log data from arbitrary locations.
By overriding getChangeLog() it's now also possible to use pre-merged
change logs. This method is also public, so users can get the change log
information and e.g. do the presentation on their own.
Link to Github contributors page for list of contributors
Update .gitignore
Update Gradle files to support uploading to Maven repositories
Update changelog in README
v1.2.0