Squashed 'docs/overview/' content from commit 373e69e

git-subtree-dir: docs/overview
git-subtree-split: 373e69e04459bb10ea6b5a4c35c624b2bb6616d4
Merge commit '7c897cb3c82d8b1dd9ed6ed2ff1219f2b109a56c' as 'docs/overview'
new version of selenium FTW\!
moving securesync/users to facility
Merge pull request #1535 from bcipolli/new-selenium

New selenium version
Merge pull request #1536 from bcipolli/refactor-securesync

Refactor securesync
Merge pull request #1531 from aronasorman/bundle_docs

Bundle Github Wiki
3 import bugs from securesync.users => facility refactoring
One more import error, one control panel bug (unrecognized facility causes exception instead of 404)
Fix for #1485 - translation of None chokes.
Fill in missing_video keys from topic tree for English videos when generating dubbed video mappings.
Merge pull request #1543 from rtibbles/missing_videos_fix

Fill in missing Video keys for English videos from topic tree when generating dubbed video maps
Prevent central server stats timelines getting broken by data with no timestamp.
Merge pull request #1544 from rtibbles/central_timelines

Skip over log data with no completion timestamp when rendering timeline stats on central server