New function get_parent_repository()

Created new function to get repository parent from a repository.
First get the info of the repo child, check if it has repo parent, and
if its true, get the repo parent.
Added option to show parent

Added checkbox at Repo Widget configuration.
Added function to work with this option (get_show_parent() function).
Show parent repos in the widget

Get the option setted at the widget configuration.
Check if the repo has parent, and if the option is checked.
Get the parent repository, and save a cache file with its info.
Added style and forked icon
Added Awesome Font for forked icon
Merge pull request #8 from naulacambra/experimental

Show parent repos