Merge pull request #4 from alexlib/imgcoord

import from alex's Imgcoord-branch
Test commiting with tortoiseGIT
changed headers for a clean implementation with '' "" ''
Started to transfer the img_coord function in imgcoord.c

I think we nedd to clear what what will be given by refernce (pointer) and what needs to be given by value.

Is there already a convention for that?
changed the function calls to new-datastructures (only cal is used in call of functions)
need to ensure when Ex_t and when Ex is to be used.
Any ideas to that?
merged epi-branch from alex into my imgcoord
updated epi.c to work with imgcoord.c
Need to clear if mm_np is given by refence or by value actually we mix it up in epi.c, imgcoord.c and multimed.c
Commit before switching the branch
took over Patrik branch
added imgcoord.c to the compilation list in CMakeLists
added epi.h to imgcoord.h to be sure we do not include something twice