Fix a regression in flip iop legacy params handling

Previously it was not always needed, but it might be
in history stack as "orientation (off)", but now we
always want it by default, so enable it.
If user want's, he can disable it.
Updated Dutch translation
Merge pull request #625 from MRIG/master

Updated Dutch translation
Fix (r2) a regression in flip iop legacy params handling

If flip iop is disabled, enable it,
and replace params with default_params.
Update French translation.
VNG4 for Bayer sensors

This brings the Bayer-specific code from dcraw into linear and VNG
interpolate, so that it can work as VNG4 for Bayer images.

also misc. cleanups:
- lin_interpolate(): don't need to offset by roi_out x/y which is set to
  0,0 by process()
- vng_interpolate(): alloc a single memory range for both buffers
Merge pull request #627 from dtorop/vng4

VNG4 for Bayer sensors
demosaic: properly capitalize AMaZE since other are capitalized too
demosaic: indicate VNG4 is slow
Fix (r3) a regression in flip iop legacy params handling

Basic Idea: if history stack has flip iop with orientation != -1,
then this history stack was, either:
1) created before regression (and had gone through legacy_params, which never produces -1), and we need to fix it!
or
2) created after regression (by manual changes to flip iop, and we should not fix it

Q: Is there a way to differentiate between these two?
rawspeed: Nikon P7000 high iso fix
letsgofloat: new IOP
Temperature iop: Fix process (Bayer)
Temperature iop: Fix process (X-Trans)
Invert iop: Fix output_bpp()
Invert iop: Fix process (Bayer)
Invert iop: Fix process (X-Trans)
letsgofloat iop: allow tiling
letsgofloat iop: implement OpenCL kernel!
Temperature iop: Fix process_cl