Merge branch 'stable-2.8'
* stable-2.8:
Update 2.8 release notes with recently merged fix
SideBySide2: Fix Reply and Done buttons
SideBySide2: Batch adjustments of padding widgets
SideBySide2: Fix misplaced widgets at bottom of window
SideBySide2: Bump z-index on the "underline" cursor
SideBySide2: Edit during single click of short drafts
SideBySide2: Allow CM3 to buffer all updates when rendering
SideBySide2: Batch updates to CodeMirror3 during onShowView
Allow user names that start with a numerical value
Change-Id: Id203f3120bef795af83a851a377a52b95baf22b2
