Fixed decimals in price

Change max to 7 decimals
Improvement on nonce

Skipped wait on nonce, now simply increase until greater then last nonce
NMC to BTC

- Introduced trade NMC to BTC to GHS or NMC to GHS optimization
- General code improvements
Various updates

Added Checkcoins, changed trade decisions, improved error handling.
Version 0.4.12

- Improved trade functions, now calculate efficiency correctly
- Improved error handling
- Start GUI Hooks
- General code improvements