Make the plugin build script for for Mac OSX

The build_server script used to build the plugin zip file was Linux
specific. This changeset tweaks the scripts such that they will also
run on Mac OSX. It also adds various .gitignore filters such that the
temporary files created by the build script are ignored by git.

Change-Id: I77cfe6bfb65be86c11beb50bcab9c345433b5a8e
4 files changed