Get rid of the virtual python-core package and instead python depends on
python-mini and provides files missing in python-mini for a full featured python
installation.
Thus also update the dependencies of various python packages.
git-svn-id: svn://svn.openwrt.org/openwrt/packages@14760 3c298f89-4303-0410-b956-a3cf2f4a3e73
