DM hot-add udev rules presence

Script for testing Hot-Add udev rules presence. VM is shut down, DM enabled
and restarted. After that a remote script tests if Hot-Add support is
enabled in the udev rules by searching after ```SUBSYSTEM=="memory",
ACTION=="add", ATTR{state}="online"``` rule.

Sample script output
```
Wed Nov 19 22:45:14 2014 : Hot-Add udev rule present: Success
Wed Nov 19 22:45:14 2014 : File is:
Wed Nov 19 22:45:14 2014 : /lib/udev/rules.d/40-hyperv-hotadd.rules
```