Revert "R4: Remove custom scrollbar use in Javascript"

This reverts commit 85d311ac62cf4f962dd779c2ee652bf0601bfa90.
Revert "R4: Add native browser scrollbars with CSS"

This reverts commit 3f7129bd9370e41cd341bda9aaa310a3b5db98e9.
R4; Begin work on dynamic scroller
R4: Dynamic scroller round 2
Comments for Tanaric
Add web_developer_mode
Remove old R3 DB support
Better README and initial setup.
Fix some problems with song scanning.
Refactor full scanning.
Start using Watchdog for monitoring
New scanner working and tested.
Reduce log spam
Work towards SQLite compatibility for dev mode
Web developer mode is now functional.  Use README!
Fix a few bugs related to on_finish
Merge branch 'master' of https://github.com/rmcauley/rainwave
Start work on real memory trace
Memory tracing using pympler
Fix dumb error.