Back button for mobile

This basically mimics "back" on iOS. No history API support yet.

closes #197 (closed)

added 1m 4s of time spent at 2018-12-05

removed time spent

added 1h 4m of time spent at 2018-12-05

Could I get a screenshot of how it looks?

vokoscreen-2018-12-13_17-52-02

added 162 commits

• 403c86e4...dbe79a3c - 161 commits from branch develop
• 610724ff - Merge remote-tracking branch 'upstream/develop' into mobile-back

Compare with previous version

super nice

merged

mentioned in commit ac60550e