Proper english. 'allows one to', not 'allows to'
gradientsliders: use NAN as value to disable display of color picker value

this allows better handling of out-of-bound values - those are clamped to
the gradient slider range but still a marker is displayed in the slider
colorin: add option to normalize Lab values to real, ie. non-virtual colors

depending on the color matrix belonging to a camera our current code may deliver
"virtual" Lab colors, e.g. pixels with negative L and high a/b values. while this
liberal handling of out-of-bound colors most frequently delivers good results, in
some cases our modules may produce serious artifacts. typically you find this in
photos showing saturated blue light sources (tell: stage photography) and when using
certain modules like "levels". the new code offers an option to normalize colors,
i.e. restrict Lab to really existing colors. we achieve this by transforming
camera RGB to linear RGB, clamping, and finally transforming to Lab. currently
if the normalize option is activated all colorin processing is done by lcms2
which leads to a significant slow-down.
colorin: extended version: fix shortcomings; enable selection of clipping profiles; implement SSE and OpenCL codepaths
Add support for audio notes playback ...

... by using an external application like 'aplay'.
This commit also stores the presence of .txt and .wav files in image
flags and updates these in the startup crawler. So if you no longer see
your text overlay: run the crawler (at least) once.
colorin: some code cleanup
Fix the use of jobcode that got removed by mistake.
This fixes bug #9789
lowpass: unbound processing
Italian translation updated
Updated Danish translation
Merge pull request #445 from bartokk/master

Italian translation updated
Merge pull request #446 from pryds/master

Updated Danish translation
chmod -x da.po
Update French translation.
Updated Dutch translation
Merge pull request #447 from MRIG/master

Updated Dutch translation
Updated Dutch translation
Merge pull request #448 from MRIG/master

Updated Dutch translation
initial implementation of slideshow view
slideshow: coarse view skeleton