Implement Unflag feature on the Package Details page
It was needed, because until this time only the Flag out-of-date option
was available there, and it could be solved without any plus line adding
in the Package Details page.
The implementation touched the following items:
* Implement unflag_out_of_date function in the aur/views.py
* Add the desired link for this operation in the aur/urls.py
* Modify the string for the relevant link in the package_detail.html
template
Signed-off-by: Laszlo Papp <djszapi@archlinux.us>
Signed-off-by: Sebastian Nowicki <sebnow@gmail.com>