Added buttons in contenteditable.

-Added buttons:left, right, justify, h1, h2, h3, remove heading, undo,
redo
-Changed psui.css to fix problems with line height in h1, h2 and h3
Created favicon.

-Created favicon
-Changed html - added link tag
Changed logo.

-Chenged color of logo
Repaired logo.

-Logo saved as plain .svg file