Move while stmt from block stmt 2 keywords to other.

Make while an other keyword (c-other-kwds) in emacs major mode instead of block
stmt with 2 keywords (c-block-stmt-2-kwds). Before this change, the indentation
for the block of while loops that did not surround the conditional in
parenthesis was broken.
Merge branch 'master' of github.com:chapel-lang/chapel into update-while-stmt-in-emacs-mode
Copy etc/emacs/23/chpl-mode.el to etc/emacs/.
Remove version specific chpl-mode.el files. They were identical.
Create symlinks for emacs/{22,23}/chpl-mode.el to preserve backwards compatibility.
Update etc/emacs/README with correct information.
rst-ify etc/emacs/REAME
Fix formatting of directory index.
Reference both .emacs and .emacs.d/init.el files.
Properly escape text snippets for monospaced font-ing.
Merge pull request #233 from thomasvandoren/update-while-stmt-in-emacs-mode

Move while stmt from block stmt 2 keywords to other in emacs major mode.

Make while an other keyword (c-other-kwds) in emacs major mode instead of block
stmt with 2 keywords (c-block-stmt-2-kwds). Before this change, the indentation
for the block of while loops that did not surround the conditional in
parenthesis was broken.

This while loop shows the issue. Before the fix, this is the indentation:

```chpl
while (x % 2 != 1) {
  writeln("nothing");
 }
while x % 2 != 1 {
  writeln("nothing");
          }
```

With this fix, the indentation is correct with and without parens:

```chpl
while (x % 2 != 1) {
  writeln("nothing");
}
while x % 2 != 1 {
  writeln("nothing");
}
```

In addition to this fix, the `chpl-mode.el` file that was copied into the 22/ and 23/ directories now
lives at `etc/emacs/`. For backward compatibility, there are symlinks in the 22/ and 23/ dirs. The
README includes updated instructions based on the new file location.

### TODO:

* [x] Verify indentation is correct on more complex programs with while loops.
* [x] Verify symlinks in `etc/emacs/{22,23}/chpl-mode.el` still work.
* [x] Verify updated emacs-lisp snippet works in `init.el`/`.emacs`.
* [x] Verify it is OK to migrate README to rst format. See rendered version here: https://github.com/thomasvandoren/chapel/blob/update-while-stmt-in-emacs-mode/etc/emacs/README.rst#chapel-emacs-mode

reviewed by @bradcray