Add support for lists in mcedit.ini; Fix default colors bug; Add chechboxes to hide specific Ores

This is a repost of pull request #410, as I've rebased the commits to a new branch onto current master.

I tried my best to follow current code's style, and to keep each commit as atomic and independent as possible.

All commits depend on 1st, 2nd and 3rd commits are independent of each other, and 4th depend on 3rd.

They are also ordered in a way that each commit provides a complete new functionality or bugfix

Some screenshots:

'Show' menu with checkboxes and tooltip:
http://i.imgur.com/RpX0r5F.png

Original, all ores checked:
http://i.imgur.com/7DML87t.jpg

Unckecking all but Gold and Diamond:
http://i.imgur.com/d1lwu2z.png

A somewhat crowded and polluted area:
http://i.imgur.com/7nd7V5g.jpg

Disabling Coal and Iron alone makes a big difference:
http://i.imgur.com/18COYaL.jpg

... and now Bedrock too:
http://i.imgur.com/RLumkwj.jpg

Finally, spotting diamonds in long range is now easy and fun:
http://i.imgur.com/M15WUBD.jpg