fix(bootstrap_sdk): Move gsutil code to release_util.sh

Sync up bootstrap_sdk with other tools by using the common upload
functions. As part of this refactor release_util a bit to provide a
truly generic upload function.
cleanup(catalyst): Updates for catalystrc

Remove the catalystrc code that updated /etc/locale.gen, it wasn't
generally effective since catalyst installs things without
CONFIG_PROTECT and therefore locale.gen always got overwritten just
before it was going to be used. Add --load-average to MAKEOPTS so
builds better manage their parallelism when multiple independent jobs
are compiling code. Disable some locking to speed up builds that use
lots of binary packages.
fix(bootstrap_sdk): Don't include cross toolchains in final tarball.

The packages have to be downloaded separately so don't waste space
including it in the stage4 tarball.
fix(update_chroot): Install sysroot-wrappers before updating toolchain.

sysroot-config will be called if anything is installed/upgraded so it
better be there and ready! :)
Merge pull request #37 from marineam/sysroot

Sysroot and catalyst updates