german translation for data-table
no english translation needed
uploaded untranslated stubs
cleaned data-table messages
removed old data-table from repo
removed debug output
moved message from JS to template
if no translation is found, use the original text, not the cleaned version
force language of job creator
Hotfix for visualization-column-charts
made core more gentle about errors in vis meta
fixed stacked-column vis meta
fixed vis title in chart editor
Merge branch 'master' of github.com:datawrapper/datawrapper

Conflicts:
	plugins/visualization-column-charts/plugin.php
documented hook class
Added a hook for visualization plugin to provide their demo datasets
Chart upload controller now use GET_DEMO_DATASETS hook to get the visualization demo datasets
Registered GET_DEMO_DATASETS into visualization plugin, added getDemoDataSets function
Implemented getDemoDataSets function into bar chart
Implemented getDemoDataSets function into bar chart