Fix 'local' installer version

[cpdt]

The installer has the option to install a local copy of Slinky (by typing local when selecting the version). While this currently does correctly run the local install-version.sh script, this script still downloads the Slinky command scripts from the develop branch, whereas it should just use the local copies of the command scripts.

The fix would likely involve adding some special handling in the install-version.sh script to copy local files instead of download them.