fixes for (1) lack of highlighting in agenda in terminal vim, and (2) lack of highlighting for g:org_todo_custom_highlights in unfolded headings
added autoload unit for checkbox lists, similar to org, added keymap for checkbox to ,,cx (need to do documentation. . .
rolled back bad fix for custom todo highlighting
(redone) fix for incorrect highlighting of TODO words in headings
incorporated Olaf Dabrunz's tweak to minimize disorientation when using <tab> to cycle headings. Thanks!
fix for todo highlights not showing up unless 'ReprocessConfigLines' executed
revised func tied to <ctrl-enter> in agenda so it initializes foldling
add _syntax on_ command to vimrc
mods to accommodate new (Mar 2013) version of Calendar.vim that uses autoload setup