suport for include in makefile

[Itai-lupo]

hello, love the project.
I have a makefile with include in it and the include also has targets in it.
something like:
in the make file:
-include $(SCRIPTS_DIR)/Makefile.tests

and in Makefile.tests

`
build_tests:
$(MAKE) $(BUILD_DIR)/include/files.json
$(MAKE) $(PCH_OUT)
compiledb -o $(BUILD_DIR)/compile_commands.json $(MAKE) all_tests

`

makeit doesn't recognize build_tests as makefile option option

I looked at the code and I think it should be an easy addition.

in utils.lua you could match include statements and then recursive iterate them and add them to the options list.

do you think it will be possible to add that? I think it will be very cool