Add C++ warnings to the build process.

configure.ac

@@ -369,6 +369,7 @@ AC_SUBST(CACA_TYPES)
 CFLAGS="${CFLAGS} -g -O2 -fno-strength-reduce -fomit-frame-pointer"
 # Code qui fait des warnings == code de porc == deux baffes dans ta gueule
 CFLAGS="${CFLAGS} -Wall -Wpointer-arith -Wcast-align -Wcast-qual -Wstrict-prototypes -Wshadow -Waggregate-return -Wmissing-prototypes -Wnested-externs -Wsign-compare"
+CXXFLAGS="${CXXFLAGS} -Wall -Wpointer-arith -Wcast-align -Wcast-qual -Wshadow -Wsign-compare"
 
 CACA_BINDINGS=""