Evens out the zoom scale such that each tick corresponds to multiplying the zoom level by a constant, adaptive factor. Closes #1943.
Evens out the zoom scale such that each tick corresponds to multiplying the zoom level by a constant, adaptive factor. Closes #1943.


abrauchli/shotwell,Sanva/shotwell-gsoc,polymeris/shotwell,Sanva/shotwell-gsoc,ritchiewilson/shotwell,damianmoore/shotwell,h4ck3rm1k3/shotwell,damianmoore/shotwell,polymeris/shotwell,jof/shotwell,jimbonator/shotwell,h4ck3rm1k3/shotwell,jof/shotwell,jimbonator/shotwell,jimbonator/shotwell,damianmoore/shotwell,jof/shotwell,h4ck3rm1k3/shotwell,ritchiewilson/shotwell,Sanva/shotwell-gsoc,abrauchli/shotwell,ritchiewilson/shotwell,abrauchli/shotwell,polymeris/shotwell