Updated config for Graph legend not to display horizontal scroll track which caused legend being not accessible in ceertain situations (e.g. when native OS scroll overlay disabled)

Refactor color picker to remove code duplicartion (introduced colorPickerFactory). Allow popver position update on content change

Unified color picker API, allowed for color specified for theme selection, updated code to changes in PopperController API

Fix for default datasource query editor

Viewers can edit now means that viewers have access to Explore

Gometalinter changes & megacheck fix

Moved gometalinter to a script instead of seperate commands in circleci file, removed megacheck and added staticcheck