Fixes #54

Now give a warning in metadynamics if grid is adjusted to fit periodicity
Mistakes in switching function input for multicolvar now trigger errors.

Fixes #53
updated changelog
Flushes by default every 10000 steps

Fixes #55
Gyration: ported the optimizations to v2.0
updated for GYRATION
Small fix in changelog
Fix changelog

important changes should go first I think
Merge tag 'v2.0.1' into v2.0-hrex