Add --enable-sailfish-access-control to configure.
Enable sailfish access control in %build.

Signed-off-by: Tomi Leppänen <tomi.leppanen@jolla.com>

Add usbmoded_is_mode_permitted function to check if user is allowed to
set given mode. Root is always allowed to set any mode. Non-dynamic
modes are always allowed for all users. Dynamic modes can be set if user
belongs to sailfish-system.

Signed-off-by: Tomi Leppänen <tomi.leppanen@jolla.com>

Check for restricted modes in common_get_mode_list and don't return them
unless allowed. Add uid parameter to common_get_mode_list to do that.

Signed-off-by: Tomi Leppänen <tomi.leppanen@jolla.com>

Add method to retrieve the uid of the sender process. This calls DBus
daemon synchronously.

Signed-off-by: Tomi Leppänen <tomi.leppanen@jolla.com>

Add method to set last seen user. Use that information to limit the
implicitly set modes. If no user has been seen yet, fallback to
charging only mode.

Signed-off-by: Tomi Leppänen <tomi.leppanen@jolla.com>

Check sender uid to deny access for modes that are restricted. Prevent
non-owner users from hiding or unhiding modes. Add
get_allowed_modes_for_user method that lists only those methods that
user may choose.

Set last seen user based on uid that has called
get_allowed_modes_for_user last. This is not a perfect solution by any
means since it can be easily confused by calling it from command line as
root but generally no user other than the active one should call it.
Later when there is a proper way to get the active user this can be
improved.

Signed-off-by: Tomi Leppänen <tomi.leppanen@jolla.com>

Limit dynamic modes to device owner

See merge request mer-core/usb-moded!55