Update for Minecraft 1.6.2 (not release ready)

Added own region file writer implementation.

Separated all region and chunk related classes so that they do not rely
on Minecraft code.

Mini map mode and zoom level is now saved to the config file.

Added dimension field to markers.

The renderer now attempts to display the map at a resolution that is a
multiple of the view dimensions in blocks. This should reduce
blurriness.

Chunk updating and saving tasks now process multiple chunks at a time,
rather than only one chunk per task.

Debug messages have not been disabled.