Improved background color for email

Now covers Windows 10 Mail
Closes out emailmonday#149

Fix right gutters in Gmail iOS+Android

Resolves emailmonday#89 … again…

Bump up version #

Merge pull request emailmonday#25 from forsbergplustwo/patch-2

Removing duplicate CSS declaration for data-table-th

Added Preheader text

Visually hidden preheader text.