Make inline matrices use the CSS style for making inline tables

Matrices were not inline before in some browsers.  This uses the proper css for inline tables (defined in CSS 2.1).
Merge pull request #83 from jasongrout/patch-1

Make inline matrices use the CSS style for making inline tables

Works for me.  I tested using a matrix answer and the matrix in the answer field was formatted with inline-table
Merge pull request #9 from openwebwork/master

Bring master branch up to date.