Adds style to public 404, 422, and 500 pages.

Inserted scholar_uc images into public folder.
Modified .html pages to include UC Navbar.
Customized error messages on page.
Included css and javascript into <head> to make Navbar function.
Changes made to HTML code to clear validation errors.
<file name>: <changes>

_title_bar: changed nav to div in order to use role="menu" and keep sub vie roles in place
_header: removed group tag (not needed) and " clear='all' " attribute from br tag (not allowed)
show: changed hgroup to div
new: removed type="textarea" and autocomplete="on" from textarea (not applicable to tag);  changed email label attribute for="email_addr" to for="email" to match input id
Adds beta banner in left corner
Merge pull request #208 from uclibs/feature/#181_custom_error_page

Adds style to public 404, 422, and 500 pages.
Merge pull request #209 from uclibs/feature/124_html5_validation_fix

Changes made to HTML code to clear validation errors.
Move UC logo to right so it is not covered by beta tag
Merge pull request #210 from uclibs/feature/#193-add-beta-tag

Adds beta banner in left corner
Update CHANGELOG for version 0.4.0
Point Gemfile to latest Curate gem version
Merge pull request #213 from uclibs/feature/update-changelog

Update CHANGELOG for version 0.4.0
Merge branch 'release'