Map Data Freeze (Added to IITC core feature to stopping map data download)

I tried to rearrange my [old plugin](https://github.com/jonatkins/ingress-intel-total-conversion/pull/584) integrating it into the core IITC. I hope that the actual result may be acceptable.

Idea for UI in IITCm:
- [from G+ user](https://plus.google.com/+FlorianSauterIT/posts/BqxykoZ1iri);
- [from me](https://f.cloud.github.com/assets/4642351/2384964/c6aabe54-a915-11e3-873e-5f894d8e5865.png);