Clean up removed files manifest in updater
Remove redundant backup package-manifest file
Rework height computations
Rework (relative) positioning
Fix up height/pos assumptions
Add FrameList sorting routines
Multiline flexbox base commit (layout)
Add flex-wrap and align-content to CSS style parser
Update some tests.
Wrap items when overflow is hidden.
Add flex-flow CSS property
Small fixup for ApplyRelativePositioning()
Merge branch 'multiline_flexbox-work'
Merge branch 'master' into Code_Cleanup
Merge branch 'Code_Cleanup'