tools.deploy.shaker: more timid global stripping

tools.deploy.shaker: more timid global stripping
Strip globals by replacing their value with "f". The list of globals to strip was written with the assumption that the stripped globals would get restored like normal hashtable keys when accessed. This isn't valid anymore with the globals optimization, since creating a new box breaks the foldable invariant between a global name and its associated box. Need to go through the list of globals to strip and find the ones that actually can be entirely removed as opposed to just reset to f. Fixes #445. Fixes #446.