Fix ae density for corehole

This patch modified the method get_all_electron_density (gaed) to give a more consistent description of the core-hole in a spin-polarized calculation. Without this patch, gaed will give a unequal number of electrons for the XCH (one electron removed from core and set to the prior LUMO), which is wrong IMHO. This patch works by assigning the core hole to alpha-spin in a spin-polarized calculation. See attached test with a XCH.