Added support for Megatronics v2.0 and Minitronics v1.0

merged from code downloaded from reprapworld.com
Fix: removed wrong ; at end of define
Fix: Long menu entries (>14 or >18 chars) caused overrun in hitachi display implementation
Merge pull request #496 from MStohn/fix-16x2-lcd

Fix: Long menu entries (>14 or >18 chars) caused overrun in hitachi display implementation
Merge pull request #495 from Gatulibu/Marlin_v1

Added support for Megatronics v2.0 and Minitronics v1.0
importati settaggi da marlin_passo_t_25
Abbassata accelerazione e velocita estrusore
Separato configurazione con e senza hotbed in 2 branch
ricalibrato steps, feedrates e accelerazioni
Aggiornato data versione
Abbassata accelerazione retrazione filamento a 2200
Abilitato controllo temperatura heatbed
Modificata isteresi sensore heatbed