Switch back to GCC 4.7 to build the ROM
fstab: remove the "check" option from data, caues hang on subsequent boots

e2fsck is having issues, which results in a hang on boot after the irst boot.

see here for details: http://review.cyanogenmod.org/#/c/48038/

Thanks for Dărescu Ionuț for pointing this out :)

Change-Id: If9e421a82f12750bb9847a57ba62587b110ec7b6