translate new messages into japanese
tweaks on japanese translation
Merge pull request #1987 from 77web/update-translation-ja

update Japanese translation
Fixed typos
Merge pull request #1997 from pborreli/typos

Fixed typos
exclude classes that not exist from loading
Merge pull request #2000 from ElectricMaxxx/exclude-not-existing-classes

exclude classes that not exist from loading
Show number of affected elements when seleting all elements
Better german translation for reset filters
Merge pull request #2002 from dbu/patch-3

Better german translation for reset filters
Merge pull request #2001 from dbu/patch-2

Show number of affected elements when seleting all elements
Update installation.rst

Wrong (old?) link for SonatajQueryBundle installation instructions
Some incorrect comments

Fixed-up some incorrect comments that were copied over.
Another typo.

Another typo
Merge pull request #2007 from ConneXNL/patch-2

Some incorrect comments
Merge pull request #2005 from kdkwiatkow/patch-1

Update installation.rst
Added CONTRIBUTING.md file
Merge pull request #2008 from Bladrak/contributing

Added CONTRIBUTING.md file
Fix bootrstrap popover for select2 field
Fix bootrstrap popover for select2 field, now ok