adding a new specialization to the mpnc models:

- it is now possible to specify the number of solved energy equations (property NumEnergyEquations). 
Either 0 isothermal
	1 standard-nonisothermal
	2 *new* one energy equation for the void-space and one for the solid
	3 one energy equation for each phase (wetting, non-wetting, solid)
	
Therefore, the boolean property EnableKineticEnergy had to be renamed to the integer property NumEnergyEquations

- solve bug in test_boxmpnckinetic


git-svn-id: svn://svn.iws.uni-stuttgart.de/DUMUX/dumux/trunk@12741 2fb0f335-1f38-0410-981e-8018bf24f1b0