Comply to CMake's CMP0037. (#267)
Comply to CMake's CMP0037. (#267)

Test target names are generated from the directory and
source filename. Now "/"s are replaced by "."s which are
allowed by CMP0037.
googlecartographer/cartographer,wohe/cartographer,googlecartographer/cartographer,damonkohler/cartographer,cartographer-project/cartographer,googlecartographer/cartographer,cartographer-project/cartographer,damonkohler/cartographer,cartographer-project/cartographer,googlecartographer/cartographer,larics/cartographer,wohe/cartographer,damonkohler/cartographer,wohe/cartographer,larics/cartographer,larics/cartographer,wohe/cartographer,damonkohler/cartographer,cartographer-project/cartographer,larics/cartographer