This commit follows f9fde567.

Fixes #13953: Remove the progress bar min-width styles for low percentages to avoid jumping progress

Fixes #12738 again: use max-device-width instead of max-width for .navbar-collapse height in landscape devices

Added @gray-base variable to make @gray-{shade} reference, also allows @gray-base to be modified with less#modifyVars and the vars to cascade

if background is not set on row, striping doesn't work properly in responsive tables where row and cells are set to  display: block.

In Sass, variable must be declared before it is used.
This also removes Miscellaneous section, because horizontal line color
and form / list paddings are Typography.

Fixes #13911