write an xbm file to the buffer

Hi,

I wrote a simple method to write an xbm file to the buffer. Use it to display an image, or use it to display menu items. The "inverted" parameter could used to mark an item active. 

Creating a XBM file is very easy using Gimp. Create an Image with the size of 84x48, monochrome and save or export it as a xbm file. Import the created file in your main.c/cpp with the include directive:
    "#include <filename.xbm>". 
Draw the image using:
    drawXbm(0, 0, filename_bits, filename_width, filename_height);

Hope you find it useful!