Merge branch 'stable-2.10'

* stable-2.10:
  Set 'line-height: normal' for lines in side-by-side diff
  Add missing documentation of the groups_members cache
  SideBySide2: Show file name in window title again
  Fix documentation of the default value for core.streamFileThreshold
  Bump version to 2.9.2

Change-Id: Ibea6f3291015f1dc707057537916e00d5a93c501