reading tables 2
Merge branch 'master' of https://github.com/PerceptumNL/KhanLatest
Merge branch 'develop' into exercises
Fix pictures in reading_pictographs_1 and 2, closes T26
Search results plurals. Closes T36
Fix multiple choices when answer is none of them
Updated line_graph_intuition.html with Khan US exercise
Hide and group distributive_property.html, closes bugherd/#55
Add exercises/geometry_proofs* from Khan US
Remove line_graph_intuition.lang.js
Merge branch 'translation' into develop
Merge branch 'exercises' into develop