Tweaked to use P4CONFIG=.p4config.local for 'p4 clone' operation only,
and then it is unset to defer to the SDP standard. This fixes an issue
where the local repo cloned from The Workshop with 'p4 clone' (using DVCS
features) was getting confused with the 'p4d' instance we were trying to
initialize.
Also updated to download 2017.1 p4/p4d/p4broker executables plus Swarm 2017.1
package.