SettingsInterface and minor improvements

v1.3

add implicit conversions to std::string and const char *

Basic EventInterface with Keyboard-, Mouse-, Motion- and Wheelevents

v1.2

add implicit conversions to std::string and const char *

Collision detection and movement

v1.1

comment out test cases during development

First stable release

This release includes:

• Image rendering
• Font rendering (dynamic font size, different rendering qualities, aliasing fonts)
• basic game loop (onEvent, onLoop, onRender)
• a movable entity (collision detection isn't implemented yet)