Support basic table styles

There is currently no way to apply styles to tables inserted from the WYSIWYG editor. Using the source editor and attempting to apply a `style=` tag to the table by hand results in it appearing correctly in the editor, the editor becoming unusable, and the table still renders incorrectly (as if the tag doesn't exist) on preview and save.

At minimum, I'd like the ability to set table width as a percentage of page width, like style="width:42%;"

This is basic formatting that we lost with the new editor.

On a side note, my ability to convince my bosses that we need to shell out $80 for a plugin to gain basic HTML features we've had for decades have been unsuccessful, and I have to say there is a certain degree of logic to their reasoning