remove hwcomposer.msm7x27a
update WiFi configs for updated BCMDHD drivers (thanks @galaxyfreak and @sachinthomaspj)
releasetools: don't include files from extras/
add debug.gralloc.map_fb_memory=1 to get build booted with new display-legacy-exp

Change-Id: Ib7cd86e905482d53e943bb5a4ff35ff70d2026c1