Make Auto-Build the Default

[freeformflow]

This has gained new interest this morning, so I'm linking it to a counterpart in Haiku9. The advantage is that it allows you to tinker more manually before pushing stuff to the Cloud. That was all good in the earliest stages of development, but less so now. Dan has a ticket in H9 to the effect of auto-builds. I think that we should retain something like a --nobuild flag, but make build the default.

pandastrike/haiku9#74