Remove unused "easier" Window navigation mappings

These would let me save a keypress when switching windows but are
unusable because Ctrl-j is used by several plugins for a kind of jump
command.
Add dokuwiki syntax by Bill Powell

This is a bit of a hack so it requires mediawiki.vim and extends it,
instead of defining its own syntax. I don't mind, it lets me edit our
dokuwiki just fine.
Extract dokuwiki filetype detection to ftdetect directory

Also deleted all filetype detection related comments from the main file.
Vimify dokuwiki mappings

  * Removed insert mode mappings for promote & demote
  * Change heading insertion mappings to latex-suite style cpital letter
    sequesnces (e.g. WH3 stands for: Wiki Heading level 3)
  * Replace ^M with <CR>
  * replace ,, with <leader>

This gets rid of every double comma mapping, which is something I don't
enjoy typing. Leader is configurable and I suspect <CR> should be more
compatible than ^M. There is also now no longer a strange pause when
typing a comman in insert mode.
Add vimwiki style mappings for header promotion and demotion
Add Dokuwiki mappings for bold, italics, etc

These rely directly on TPope's Surround plugin to surround the current
word sith symbols twice, providing mappings for bold, italics, underline
and code.