Merge IE7 and IE8 SCSS for Base

Updated refrences in dependant files
Merge IE7 and IE8 SCSS for Grids

Updated refrences for imports
Merge IE7 and IE8 SCSS for CLF theme

Updated import statements
Merge IE7 and IE8 SCSS for GCWU theme

Updated dependant imports in Intranet theme
Merge IE7 and IE8 SCSS for Intranet theme

Update import statements and used a placeholder to reduce duplication
No units for zero values
Merge pull request #1023 from nschonni/remove-zero-units

No units for zero values
Merge pull request #1020 from nschonni/merge-ie-scss

Merge IE7 and IE8 SCSS
Resolved merge conflicts. Extended IE7/IE8 SCSS consolidation to other themes.
Travis build 3517702 pushed to gh-pages
Travis build 3524418 pushed to gh-pages
Travis build 3532418 pushed to gh-pages
Travis build 3534427 pushed to gh-pages
Travis build 3537918 pushed to gh-pages
Travis build 3543300 pushed to gh-pages
Travis build 3543321 pushed to gh-pages
Travis build 3556642 pushed to gh-pages
Travis build 3557427 pushed to gh-pages
Travis build 3593884 pushed to gh-pages
Travis build 3595883 pushed to gh-pages