mangle refactoring

revert windows C++

revert windows C++ p2
move c++ mangle from backend to glue in windows

experemental cpp+d test

fix test fix 3

fix test fix 4

fix test fix 5
reworked visitor, added simple cpp test

rebase
improve d_do_test

fix d_do_test.d

remove old cpp tests

remove trailing spaces
basic template support + comments + tests