WP LaTeX: Fix strict Error.

> Strict Standards: Redefining already defined constructor for class Automattic_Latex_DVIPNG in .../automattic-latex-dvipng.php on line 93


git-svn-id: https://plugins.svn.wordpress.org/wp-latex/trunk@982248 b8457f37-d9ea-0310-8a92-e5e31aec5664
WP LaTeX: Ditch `attribute_escape()`


git-svn-id: https://plugins.svn.wordpress.org/wp-latex/trunk@982253 b8457f37-d9ea-0310-8a92-e5e31aec5664
WP LaTeX: Ditch `clean_url()`.


git-svn-id: https://plugins.svn.wordpress.org/wp-latex/trunk@982254 b8457f37-d9ea-0310-8a92-e5e31aec5664
WP LaTeX: Ditch `_c()`.


git-svn-id: https://plugins.svn.wordpress.org/wp-latex/trunk@982255 b8457f37-d9ea-0310-8a92-e5e31aec5664
WP LaTeX: Ditch `wp_specialchars()`.


git-svn-id: https://plugins.svn.wordpress.org/wp-latex/trunk@982258 b8457f37-d9ea-0310-8a92-e5e31aec5664