Adapt to tizenorg: Generate app label from pkg_id

Adapt to tizenorg: Generate app label from pkg_id

Add "generate_app_label" internal function, which is currently a stub that
always returns label: "User". This is temporary solution, the function will be
implemented for both Tizen IVI and Mobile profiles using preprocessor
directives and compilation macros.

Function is used in libprivilege API functions that use pkg_id,
app_name or equivalent parameter.

In addition, instructions in "perm_app_uninstall" and
"perm_app_revoke_permissions" are temporary commented out. These functions
will be restored when the libprivilege database is able to keep the same label
for all installed applications and uninstall/revoke them separately.

Change-Id: I1ee2f564f033536a672fe56110e10d507ad8f269
Signed-off-by: Marcin Lis <m.lis@samsung.com>