Replace PWD with CURDIR in Makefile
Replace PWD with CURDIR in Makefile

... so that it is possible to invoke make with -C flag from another
directory.

iliastsi/Concuerror,parapluu/Concuerror,mariachris/Concuerror,mariachris/Concuerror,aronisstav/Concuerror,parapluu/Concuerror,aronisstav/Concuerror