Explicitly declare documentation files as Org files

Renames: NEWS, TODO and README files.
README was a symlink to README.org, removes the symlink in favor of
simply keeping the Org file.

TODO.org

@@ -0,0 +1,21 @@
+#+TITLE: A list of important / desirable tasks
+
+* pdf-isearch
+** Allow for entering multi-byte characters with some input-methods.
+The PDF buffer is in uni-byte mode. It prohibits the user from inserting multi-byte characters in the minibuffer with some input-methods, while editing the search string.
+* pdf-forms
+Recent poppler versions have some support for editing forms.
+* pdf-annot
+** Updating the list buffer is too slow
++ Update it incrementally.
++ Possibly skip the update if the buffer is not visible.
+** Make highlighting customizable
+* epdfinfo
+** Maybe split the code up in several files.
+* pdf-view
+** Provide some kind of multi-page view
+** Make persistent scrolling relative
+Currently the scrolling is kept when changing the image's size (in pdf-view-display-image), which is actually not so desirable, since it is absolute. This results e.g. in the image popping out of the window, when it is shrunken.
+* pdf-info
+** Add a report/debug command, displaying a list of open files and other information.
+** Use alists for results instead of positional lists.