Adding starter code for using SDL library for a windowed/interactive mode.
Moving mandelbrot coordinates into coordinates structure.
Adding function for zooming the coordinates in or out.
Adding ability to zoom in and out via scroll wheel.
Adding image save to file when 's' key is pressed.
Adding variable to keep track of when to render the output so we don't bother rendering when nothing has changed.
Allowing window to be resized.
Window size is restricted so it won't be larger than the allocated size.
Separated out the png generation in order to simplify ons creen rendering by not requiring any malloc.
Adding '-nw' option for no window mode.
Adding ability to pan by click and dragging.
Switching from SDL method SDL_RenderDrawPoint() to SDL_LockTexture() for performance improvement.
Adding in debug functions for printing variables, and timing.
Adding method of setting depth based on level of magnification.
Adding new feature to render at 2x to speed up rendering while panning and zooming.
SDL Texture is now only reallocated when the window is resized.
Fixing problem with the depth controls.
Updating Readme to reflect new windowed mode using libsdl.