Initial commit, based on Martin Väth's zram-init scripts
Change zram_num_devices to num_devices

In Linux 3.2 and 3.3 only, the parameter is called "zram_num_devices" Every other version of Linux (up to the current version 3.8) uses "num_devices" as the parameter.
Support further options (Thanks to Sven Eden). Add systemd support
Support umount/stop for commandline and systemd. Fix several typos.
Improve documentation (e.g. more swaps for more processors)
Fix umounting