Work on naming conventions (with help from Mirka, thanks!). The old methods...

Work on naming conventions (with help from Mirka, thanks!). The old methods still work but are deprecated now. Here is a rough overview of old names -> new names

SubTypeTag1 -> SubDomain1TypeTag
SubProblem1 -> SubDomainProblem1
subProblem1 -> sdProblem1
subModel1 -> sdModel1
Common -> SplitAndMerge
MDGridView -> MultiDomainGridView
MDGrid -> MultiDomainGrid
SDGrid -> SubDomainGrid
SubProblem -> SubDomainProblem
subID1_ -> sdID1_

Reviewed by Martin

git-svn-id: svn://svn.iws.uni-stuttgart.de/DUMUX/dumux/trunk@12190 2fb0f335-1f38-0410-981e-8018bf24f1b0