Install required libs

[brolund]

I had to execute:

sudo apt-get install libxcursor-dev libxdamage-dev libxinerama-dev libxtst-dev

before being able to run make, but after that it works like a charm.

[liskin]

You're not suggesting the makefile should do that for you, are you? :-)

[brolund]

Not at all, I just thought it might be good info to put someplace, perhaps in the readme? :-)

Didn't have the energy to make a fork and a pull request only for that. ;-)