Some small crbuild fixes
make vm-build.sh as executable
Under Ubuntu /bin/sh no longer points to bash. Because the build environment depends on running within bash, we use /bin/bash instead.
Catching un-initialized variables leads to an
"Unbound variable" error in the "process_options"
function in "build/android/envsetup_functions.sh".
Default value for CPUS env. variable
Merge pull request #1 from openresearch/master

crbuild fixes