Rename reserved word variable in googlemaps.js
Rework gzipping of jsgui resources

Uses an ant gzip task rather than the custom bash script that breaks
the build on Windows.
Hardcode "/tmp" in BCKeys.INSTALL_DIR

Intended to fix issue #1402
Merge pull request #1410 from sjcorbett/jsgui-windows

Fix jsgui build on Windows take 2