Fix all possible URL constant issues for once & forever

Better to use trailingslashit() to make it consistent everywhere
fix all "false positive" ThemeForest Check

it is important if you want to submit your theme to ThemeForest.
Additional function name changes has been done on codeeditor.php for
consistent naming purpose.
fix silly "false positive" Theme Check result

I know Theme Check is not perfect for all situation.
Fix another Theme Check issue

INFO: Non-printable characters were found in the alchemy.php file. You
may want to check this file for errors.

Line 515: $html .= '<a href='#' class='button button-large docopy-' .
$name . ''>'. __('Add More'��� 'vp_textdomain') . '' . $group['title'] .
'</a>';
Merge pull request #22 from agusmu/master

Fix all possible URL constant & false positive Theme Check issues