#4 Adaption for compiling under Linux

[FranzHeinz]

The code doesn't compile under recent Linux-distributions anymore. There is a fix to this I found at this website: https://www.holarse-linuxgaming.de/wiki/zod_engine

It seems that in order to compile with recent versions of the needed libraries, the code hast to be adapted.
Install libraries unter Ubuntu 16.04.5 LTS:
sudo apt-get install libsdl-image1.2-dev libsdl1.2-dev libsdl-ttf2.0-dev libsdl-mixer1.2-dev libmysqlclient-dev libwxgtk3.0-dev build-essential

Change row 251 in /zod_launcher_src/zod_launcherFrm.cpp to:
check.replace(i,1,1, (wxUniChar)'_');

Now compiling seems to work again,