Version 2.0 Beta

This release fixes a lot of things that were broken in ZBatt and in it's configure.ac file. ZBatt should now build without any issues on most BSD systems and Linux v2.4.26+.

I also fixed a bug where if /sys/class/power_supply didn't exist under Linux, ZBatt would segfault; instead an error message is now displayed to the terminal saying that the system is either a virtual machine or doesn't have a power supply.