fix crash and log error when CyanogenMod Privacy Guard is enabled

Because GPG is all based on the Contacts stuff, GPG will not work when CM
Privacy Guard is enabled since it blocks the app's access to Contacts.

fixes #3225 https://dev.guardianproject.info/issues/3225
quadrupling the amount of #ifdef variations cppcheck will try

GnuPG libs have a lot of #ifdefs, so we need a lot more than the default of
twelve.  This will probably also double the amount of time cppcheck takes
to run.
jenkins-build: only feed .c and .h files to cppcheck

Before, cppcheck was trying to check Makefiles and *.patch, so stop that ;)

Sort the file list since cppcheck checks the files in the order that it
receives them.
tests: update to latest Guardian Project keys and redo detached sigs

The signatures were out of date so I updated everything.
add app description to manifest to support p2p distribution

This allows other methods of distributing APKs to also include the
description text, like the FDroid local repo swapping.
fix grammar in description  (thanks kingu for reporting!)