465eb72: Fix rebuilding librbspeex on OS X and make rm work on Windows.
OS X ar operates on fat libaries and cannot update existing archives. Remove it first to avoid this. Use a make function when removing files to allow calling the correct command on Windows, which doesn't know about rm.
5f5d7f6: Fix path creation for zip file names in current folder.
When building in the current tree (i.e. buildfolder ending up as '.') creating the filename to use in the zip file stripped all '.' characters. Use a different way to create the filename to avoid this.