Squashed 'theme/zebra/' changes from ba089a9..0f496a7

REVERT: ba089a9 One more change to top nav
REVERT: 6e8e30e Fixed black navbar on page load (zebra)
REVERT: 32de614 Navbar styles: home icon, all caps, smaller type
REVERT: 9c1c7e0 1) pull add'l css styles from LMS into custommenu.css 2) remove nav borders @bunderwood
REVERT: 6253e50 Flatten navigation bar theme & swap for smaller header logo with more margin. @bunderwood
REVERT: f351b9c fixed menu links
REVERT: af2cfad update navbar welcome link to customHomePage from config.php
REVERT: 77c300b added new images for @bunderwood theming
REVERT: 9990280 added errorbox css for maintenance warning
REVERT: e783e6b tweaked after 2.5 upgrade
REVERT: 9ce3860 Update past, future url to use querystring
REVERT: f5d5787 Fix bad merge. updated login header implementation
REVERT: 9da343f Updating 'Current Courses' to use semester query string
REVERT: 9dd4268 Merge branch 'SEBTS_RELEASE' into SEBTS
REVERT: 0c12ca0 added Writing Center menu
REVERT: e5cd8e8 added Writing Center menu
REVERT: 053a751 Merge branch 'SEBTS' of https://github.com/sebts/moodle-theme_zebra
REVERT: a5eb544 Merge branch 'master' into SEBTS
REVERT: 1bcefcd Added STR 4.1
REVERT: 47a261a SEBTS customizations

git-subtree-dir: theme/zebra
git-subtree-split: 0f496a7151b2a74441703feb9e5325b5d6803f7e
Revert to default zebra v2.5.0
SEBTS customizations
Added STR 4.1
added Writing Center menu
Updating 'Current Courses' to use semester query string
Fix bad merge. updated login header implementation
Update past, future url to use querystring
tweaked after 2.5 upgrade
added errorbox css for maintenance warning
added new images for @bunderwood theming
update navbar welcome link to customHomePage from config.php
fixed menu links
Flatten navigation bar theme & swap for smaller header logo with more margin. @bunderwood
1) pull add'l css styles from LMS into custommenu.css 2) remove nav borders @bunderwood
Navbar styles: home icon, all caps, smaller type
Fixed black navbar on page load (zebra)
One more change to top nav