Summary:
It can be useful when debugging infer or the Makefiles themselves to see what
`make` is doing. Instead of editing Makefiles to remove `@` now you can `make
VERBOSE=1`.
This is just `git ls-files | grep -e Makefile -e '.*\.make' | xargs sed -e 's/^\t@/\t$(QUIET)/' -i`, and adding the definition of `QUIET` to Makefile.config.
Reviewed By: jeremydubreil
Differential Revision: D4779115
fbshipit-source-id: e6e4642
Jules Villard