envsetup: new function cmka

- The build system adds a clean-<module> target
  for each module / package.
- This utilizes that and cleans and builds using mka.
- If no argument is supplied, it runs "mka clean".
- If argument is (bacon|otapackage|systemimage), it
  runs installclean.

Change-Id: I582ac2f92df3278c41c254c73e9c02ad7f406851
(cherry picked from commit eb74c2f2b9bb708e77edfdbb8ba0d0b716fef2fc)
(Also sneak in another minor change, a help entry for mkap)
releasetools: clean up residual targetfiles-* dirs in /tmp/

Change-Id: I3792307663f8a85513e102c8bf3d78cf4e514760
build: Set QCOM global cflags for secondary arch

Change-Id: I637d94f9b0ddee2c8d6057de44355e482163dd36
build: Fix copypasta in 2nd target clang flags

Change-Id: Ieedce8754b145e53d72a5d6a4b41fbe5cdf6473f