Developer Setup Guide: Add setup documentation, helper scripts and privateconfig template
Documentation: PrivateConfig Setup Guide
Build: Environment scripts cleanup
 * Add search for git.exe if GIT_PATH not set/invalid
 * Offer to save GIT_PATH when found (8s timeout)
 * Encapsulate setting user environment variables (SetEnvVarHKCU.cmd)
 * Encapsulate locating of GIT_PATH (LocateGitPath.cmd)
 * Add glitter script to flash console when Bad Things happen
 * Display warning if using setup template PrivateConfig
 * Offer to display the PrivateConfig setup guide on GitHub
Merge branch 'master' of https://github.com/RareCrowds/OpenAdStack
Build: Change OpenAdStack.PrivateConfig envar to OpenAdStack_PrivateConfig for msbuild compat