Added toggle to collapse sidebar
Revert "Added toggle to collapse sidebar" due to old code in commit

This reverts commit 9440e432de91816b5c7d72ea4e12038f88e87bed.
Added toggle to collapse sidebar (without old code this time)
Made toggle arrow longer & removed unneeded DOM manipulations
Added cmrn to contributors
merged upstream changes
Merge pull request #81 from cmrn/collapsable-sidebar

Collapsable sidebar (patch by cmrn)