Various logic fixes to options UI; corrected error where header was always suppressed; updated TCPDF to 6.0.062; updated readme to include current to-do items; started work on LTR/RTL shortcodes and TCPDF opts shortcode (not functional); started work on upgrade facility (not functional; currently disabled).

git-svn-id: https://plugins.svn.wordpress.org/wp-post-to-pdf-enhanced/trunk@875893 b8457f37-d9ea-0310-8a92-e5e31aec5664