Implemented more safety/sanity checks:
*Check for NO$GBA footer when size is normal(i.e. footer replaces end of image, not appended to it).
Yes, such image works in NO$GBA!
*Check if battery level is below 50%(2 bars), allow to proceed if charger connected.
Changed order of messages while writing nand to properly ask to not disconnect charger if it is connected.
In same place altered block counter to actually state that it is operation progress.
*Check for match of file and NAND sizes
*Check for precence of MBR in file(this means that file is not encrypted)
Added user-friendly message for successful finish of restoration.
Edited messages a bit in restore function.
Fixed building on last devkitARM(nand_WriteSectors const buffer in declaration).
Changed version to 1.6.1 to differ from base.
