Don't make assumptions about the formats of build descriptions

Change-Id: Id83a7594e9e1b9b4ffbdbaba695506d8d0d21a46
For user builds, use a release build id in the description if one exists

Companion change to Ic5913e587400dd38c04aa05de3a7becced77a59e

Change-Id: If5edbf56d567701f96f0ba46af9a90ffa8310c24
envsetup: Fix remote functions to deal with symlinks

Change-Id: I6f35dc30dda22149b2c37e1c6c7d41ea7239d3bb
roomservice: Fix assumptions about the branch naming

We can't just split from the last slash anymore, since we're using
those to distinguish the stabilization branches

Change-Id: Ia175dd317f508e99b275b56e9c83bd4729a75ddb