Request for an improved signature spoofing patch for KitKat

Please add a patch like these (mainly for KitKat, maybe later can be extended to other versions) with:

• Option inside developer options to enable/disable signature spoofing globally though developer options (disabled by default).
• Option inside developer options to limit signature spoofing to system apps (when enabled it block the installation of user apps that require signature spoofing, if they are already installed it should unistall them after asking to the user when the option is toggled on).
• During installation of apps that require signature spoofing store somewhere the name + the original signature (not faked one) and display a list of apps that have requested this feature somewhere (it may also be showed with command line, a GUI isn't strictly needed altough appreciated).

If you don't want to do it directly because you are busy for example please leave this opened so others can do it.

No files or tests are named. Start by reviewing the linked microG patches and the KitKat developer-options and app-installation paths; then determine where the requested controls and signature records belong. Done means the three requested behaviors work for KitKat, including disabled-by-default controls, user-app handling, and recorded original signatures.