- Set the selected map blinking color to a darker one

- Improve zs_mapvote_prefixes cvar description

Quick test

- Fix typo

- Expose allowed map prefixes with a new cvar;
- Increase default voting time from 12 to 15 seconds.

Ops... I commented the line that actually changed the map.

- Fix missing nil check

- Compact the window near to the top
- Decrease map options from 12 to 10
- Show the map thumbail when the cursor hovers its name

- Fix minor issue 3 (I need to sleep)

- Fix minor issue 2