Optimization of breadcrumb list and bug fixes

【Contents of fixes】
■Adjusted the display style of the category widget (when the drop-down display is off).
■Apply microdata format structured markup recommended by google to breadcrumb list code.
■Fixes to resolve console error when displaying in responsive mode.
■Fixes to display footer SNS buttons on smartphones.

The following are the files that have been modified for this update.
【Corrected files】
404.php
archive-press.php
breadcrumb.php
footer.php
function.php
single-press.php
style.css
style_pc.css
style_sp.css
【Added files】
fonts/design_plus.eot
fonts/design_plus.svg
fonts/design_plus.ttf
fonts/design_plus.woff
functions/quick_edit.php
images/style_sp.css

For details, please see the download site for purchasers of NEXTAGE (tcd021).