Add build type ASAN to compile with address sanitizer from libasan.
Details
Introduces a new cmake build type called 'ASAN'. In addition to the flags activated by 'check', with build type enables address sanitizer from libasan.
Why is it needed
Using the address sanitizer is helpful during development for tracking down invalid memory access beyond array-bound checks. It has no value for general use, but defining this build type can be convenient in some fringe cases. I do not see any downsides to introducing it?!
Authors
Nils Wittemeier