Merge pull request #534 from MRIG/master

Updated Dutch translation
Avoid flickering of stars and drop shadow for zoom == 1

This commit avoids the nasty flickring of the stars and the drop shadow
when scrolling through images at zoom level 1 or full preview (z)
Histogram refactoring
Prefer gboolean
introspection: new helpers to access array/struct

WARNING: this changes dt_introspection_access_array()
TODO: support unions
Merge pull request #511 from LebedevRI/histogram-refactoring

Histogram refactoring
Usermanual: mention slideshow view and overwrite on export
Multiple instances: move module name creation into function and use it
ImageIO Format PFM: fwrite one line at a time (based on series of performance measurements)
Collect images: allow collecting by geotagging (is coordinates set)
zonesystem: make the preview more consistent; should fix #9916
Merge branch 'master' of ssh://github.com/darktable-org/darktable
Free memory allocated by dt_alloc_align() using dt_free_align(), not free()
Merge pull request #526 from LebedevRI/pfm-speed

PFM: change write algo
usermanual: start work on version 1.5
Merge pull request #537 from LebedevRI/colollect-geotagging

Collect images: allow collecting by geotagging
Get rid of a hard coded array size
Update French translation.
No need to handle tagxtag since we are using triggers.
No need to alloc them each time, let's use stack here + fix 2 big leaks