v23/profile: The go_ppapi compiler is now hosted on googlesource.com.
v23/profile: The go_ppapi compiler is now hosted on googlesource.com.

This CL gets rid of the the checks for .hgrc, and clones the go_ppapi
repo from vanadium.googlesource.com.

A function to clone a git repo has been factored out.

I tested the web and android profile setups, and they succeed.

Change-Id: I951278636774dc8e308b695e4176c7f1753cd676

vanadium/go.devtools,vanadium/go.devtools,vanadium/go.devtools