blending: new method to populate blend mode combobox

this opens a way to have color space specific blend modes
Update Polish translation
cache: add more detailed fetch/hit/miss usage stats
Merge pull request #242 from adsr303/plpo

Update Polish translation
demosaic: new amaze from rawtherapee hg20130604
Italian translation 'cosmetic' update
Merge pull request #244 from bartokk/master

Italian translation 'cosmetic' update
Bump min version of glib to 2.30

This fixes #9450.
blending: add blend modes "Lab lightness" and "Lab color"

Both modes are exclusively offered for modules in Lab color space (so in fact for
most modules). They blend lightness and color without color space conversion and
without clamping. If you experience artifacts with the standard lightness and
color modes, try out these two.
blending: fix logical hickup in last commit
cacorrect: new code from rawtherapee hg20130605
(cherry picked from commit 9cd695b2d4609ac3973860afaae7bcf89b0fff87)
Merge branch 'master' of https://github.com/darktable-org/darktable
darkroom: at 200% zoom don't interpolate
rawspeed: get nikon coolpix p330 from rawspeed svn
(cherry picked from commit 9e49e93dba55c01ac9ff5aba632377262f2e4a36)
demosaic: don't forget amaze _OPENMP ifdefs
(cherry picked from commit 2a4f714e225ea4afcf83acc44d96ee6cd501cfd6)
opencl: fix bug in priority string parser
opencl: stop use of opencl in case of serious problems and inform user
lens iop: Enable by default, and automatically set scale.