Lists packages not found that were given explicitly.

When the user calls repogen or binarycreator using the include or
exclude parameter, those packages that were given but could not
be found in the packages directory are now listed in a warning.

Task-number: QTIFW-233
Change-Id: Iaadd0a14d2c6d834daa6dbe956118d674e048fac
Reviewed-by: Karsten Heimrich <karsten.heimrich@digia.com>