lighttable: temporary fix for position setting, global to all users.
(cherry picked from commit 0e00e394cd39d140a805424a5ea996d0287b9f07)

Conflicts:
	src/views/slideshow.c
replace int by size_t when referencing buffer size in a few places

darktable has various issues when working with huge image sizes. one of the problems
is fixed now but others still remain.
(cherry picked from commit 949ae8ae6ba4704ea330bf34279a593eaf491fba)
opencl: add kernels for the bloom module
(cherry picked from commit d79a590f22e60fe9de01dc0b4b40cd426c13324a)
interpolation: another fix of int -> size_t

probably a lot more will be needed all over the code
(cherry picked from commit 79f7e159ffa7485c630de02a3b6f6e04f41087e3)
huge images: fix issues in pixelpipe, tiling, opencl, blend, gaussian, bilateral

still pending: masks, all modules
(cherry picked from commit c8912f3acecf89a7865dcec21ce5a5b56a257b54)
huge images: fix issues in masks
(cherry picked from commit cf56f3289f9e494b6f370bd6be8bd9c0c3a99bdb)
slideshow: process images, click left and right
(cherry picked from commit a3f9e37be69a6f44432fb930458b371b5554d9f0)

Conflicts:
	src/views/slideshow.c
tonecurve revamped

we no longer clamp the a and b channel when using the corresponding curves.
instead an extrapolation is applied at both sides of the curve. this fixes
possible hue banding and artifacts mainly for images with certain highly saturated
colors (think of blue illuminated buildings at night, stage photos etc.)

as usual existing history stacks are kept untouched - if you want to take
advantage of the improvements for those you need to reset the tonecurve module.
(cherry picked from commit d9bc6218c917f3f79602a59f4c3a527ff2cad5d9)
huge images: fix issues in most iop's

exceptions: amaze demosaic and cacorrect
(cherry picked from commit 752aa50b734a5a459a070c9be2ddaaad9b8e92cb)
Deflicker: prerequired changes to the core

1. We need to know original(uncorrected) black level and white point from raw image.
2. We need a way to modify histogram precision - 64 bins is definetly not enough.
(cherry picked from commit b371275ff2c26cf274fba42b0a06d2e8d818ffbe)
huge images: imageio and the like
(cherry picked from commit 72b11b23e852da394e10f64c639c07dcd4e39776)
increase default value of maximum_number_tiles to 10000
(cherry picked from commit 894203af175ac43c6b0396e05f36d4cb8d74af1f)
fix xml bug in last commit
(cherry picked from commit e565789747b307522f3f26797e94bfdfbc42d4e6)
denoiseprofile: fix size_t striding issue
(cherry picked from commit a987fc57371ef51a2881290317f1a6a28d89b28d)
denoiseprofile: better fix, more in the spirit of the original patch.
(cherry picked from commit 96fb0985e40c102f6d945ab58ae5d452abbe0586)
huge images: use size_t in 1:1-path of pixel interpolator
(cherry picked from commit defc3ede4759fbee1c1344eeebe4eae63d21e2a4)
huge images: fix bug introduced into masks (path shape)
(cherry picked from commit 65e85745a4e400846df097d05bd910b447a7751d)
Fail compilation when comparing unsigned < 0
(cherry picked from commit be95a8686db5a2e272aaf97b7427e9c5b05542f2)
Allow compilation with gcc < 4.8

Those seem to assume that enums are unsigned by default so comparisons
like "< 0" cause a warning == error.
(cherry picked from commit b4ecc10766d93f41c12a9e271db2ffd1fe3165a2)
blend: fix unsigned/int issue discovered by houz' recently added checks
(cherry picked from commit 94b40d91bee7bf886f2f45d3f3164a18b6802b51)