performance + stability improvements + leaderboard

performance and stability fixes:

• unified usercache
• proper deletion of obsolete cache documents
• load trip diary without waiting for tour model
• remove obsolete plugins to improve app load time
• stats on app navigation

Leaderboard!

Leaderboard	Icons moved

Note that we skipped a version because I was trying to investigate
e-mission/e-mission-data-collection#141
I bumped up the version one more time and then forgot to restore it before pushing to the stores.
So v1.4.0 it is!