Eliminated some circular include file dependencies. Also thrown out a bit of dead code.
Gotten rid of legacy VECTOR type for good.
Merge branch 'hotfix/image_pattern' into refactor
Refactored blend map handling
Removed the hard-coded limit of 256 blend map entries along the way.
More work to follow.
Merge branch 'master' into refactor
Further refactoring of blend map handling. Also got rid of legacy data types COLOUR, RGB and UV_VECT for good.
Merge branch 'master' into refactor
Replaced `SMALL_COLOUR` legacy type with new type `PhotonColour` based on new class template `GenericRGBEColour`; also employing this new type in Radiance HDR image file reading & writing.
More colour data type refactoring.

Now using different dedicated colour data types for:
- parsing (legacy RGBFT format)
- front-end result image processing (RGBT format; the front-end never actually used the filter channel)
- render engine colour math (currently RGBFT format; intended to be later replaced with RGB colour + RGB transmit)
Minor refactoring (quality level, experimental feature warnings) to eliminate povrayold.h.
More colour related refactoring.

Render engine is now almost entirely unaware of the colour model used (currently still RGB, but a spectral model might be a future option).
Also "unbundled" colour and filter/transmit information in many places, in preparation for full-colour transparency computations.
fix photons bug introduced with commit 'eca922a2819fabbadd82c31e4bfadaa0c425b5b5'
Merge branch 'hotfix/photons_eca922a2' into refactor
Merge branch 'refactor'