SCSSLint: Fix ZeroUnit

Currently need to exlude the social media icons due to a false positive
in the YouTube data URI
SCSSLint: Fix SpaceAfterPropertyColon

Only use a single space after property colon
SCSSLint: Use Shorthand

Collapse property values to shorthands where possible
SCSSLint: Fix SpaceBeforeBrace
SCSSLint: Fix DuplicateProperty

Probably left over from a merge resolution
SCSSLint: Fix DeclarationOrder

Keep rule selectors together
SCSSLint: Fix HexFormat

Use lowercase and shortest possible hex colours
SCSSLint: Fix BorderZero

Use zero rather than “none” for clearing border
SCSSLint: Apply ColorKeyword

Use hex codes for colours, rather than named colours
SCSSLint: Enable CapitalizationInSelector

Need to exlude the social media centre because of overriding the
dataTables class
SCSSLint: Apply PropertySortOrder

- Alphabetizes properties
- Removed very old FF vendor prefixing from messages.scss since the
support for those was long since dropped
SCSSLint: Apply SingleLinePerSelector

Combined a few duplicate selectors too
SCSSLint; Apply EmptyLineBetweenBlocks

Minor selector cleaning during spacing operation
SCSSLint: Apply FinalNewline

Ensures that all files contain a final newline