When compiling on linux, use GNUInstallDirs to automatically determine
the appropriate libdir path for multi-arch builds instead of hardcoding
lib/ or lib64/. GNUInstallDirs should follow the FHS appropriately for
non-debian platforms that place libs in lib64/. This also removes the
need to specify `lib64` on the command line when building for a
non-debian system that follows the linux FHS.

When compiling with cmake directly on debian and specifying
`-DCMAKE_INSTALL_PREFIX=/usr -DCMAKE_LIBRARY_ARCHITECTURE=<arch>`, the
libdir should be set to /usr/lib/<arch>/.

On recent Ubuntu, 'time' is provided either by the 'time' package, or as a bash builtin. It's not present in sh, or installed by default. This causes 'pip install keystone-engine' to fail.

So, one of the following needs to happen:
-'time' package is added to the pre-reqs
-switch this script to bash
-remove the 'time' call around make

I've axed the call to 'time', but really whatever you think is best.