zaurus-updater: Unified version for all PXA zaurus models - close #1526

zaurus-updater: Unified version for all PXA zaurus models - close #1526
Works on: c7x0, tosa.
Unknown status on: poodle, akita, spitz.
Supports:
- file size checking (no more flashing too big kernel or too big rootfs)
- bigger rootfs for c760/c860 (128MB Flash instead of 64MB in other c7x0 models)
- flash writing (kernel, rootfs) and microdrive writing (only for spitz models)
Changes by:
Marcin 'hrw' Juszkiewicz (idea, code cleanup, functions split)
Dmitry 'lumag' Baryshkov (fixes and Tosa support)