Cleanup Makefile and add more warnings.

Makefile

@@ -20,7 +20,9 @@ UFLAGS =
 #       hence we ignore the incompliance in our code.
 # NOTE: We allow function declrations with specifying void
 #       (ex, void test() is allowed).
-FLAGS = -ansi -pedantic -pedantic-errors -Wno-long-long -Wno-overlength-strings \
+FLAGS = -ansi -pedantic -pedantic-errors -Wno-long-long \
+		-Wno-overlength-strings -Wincompatible-pointer-types \
+		-Wint-conversion -Wimplicit-int-float-conversion  -Wformat \
 		-Wno-strict-prototypes -Wall -Wextra -fno-caret-diagnostics \
 		-fno-show-column -Wno-missing-field-initializers \
 		-Wno-unused-function -Wno-unused-parameter -Wno-unused-variable \