being able to resume a build using an idle slave
check if locks is available before starting Acquire lock step
selecting a random slave before trying to acquire locks
Merge branch 'katana' into buildSlaveLock
resume build on available slave
Merge branch 'katana' into buildSlaveLock
try finding another available slave when resuming a build
'Waiting for build slave' text
Merge branch 'front-end' into buildSlaveLock
Change waiting for locks / Acquire Builder Locks  to something more meaningful
Change lock -> buildslave
When releasing the build slave lock notify that the slave may now be available to start a build.