Added makefile for linux build, had to remove an unused(?) file to keep ...

Hi, i got TrenchBroom to build on linux with the standard wxwidget 3.0 available on current distros, and without using codeblock, here's the Makefile i used.

To keep things simple I had to remove a cpp file that was not included in the codeblocks build file, i hope it isn't really used anywhere.