Update theme_essential.php
minor change to z-index of custom menu
Fixing custom icons on manage courses screen
Fix for indenting of categories
Merge pull request #96 from leblangi/master

Fix the ability to set custom category icons.
Merge pull request #93 from felixod/patch-27

Update theme_essential.php
Fixing social network icon display
minor allignment fix
Fix minor icons layout and margins.