README: Clarify project status.
[docs] [doxygen] Use FULL_PATH_NAMES = YES.

This causes some lists which were flat alphabetized lists of file
basenames to become nested and show the actual directory hierarchy.
[docs doxygen] Set STRIP_FROM_INC_PATH.

Without this option set, the documentation for a class in
e.g. `klang/AST/ASTNodes.h` will have doxygen say
`#include <ASTNodes.h>` on that page's documentation. With this set and
the appropriate directory specified, it now properly says
`#include <klang/AST/ASTNodes.h>`.

There's also the issue of having doxygen use "quoted" rather than
"angled" includes for this. E.g. print it as
`#include "klang/AST/ASTNodes.h"`
which is what the include lines for this file look like in our codebase.
[docs doxygen] Set HAVE_DOT = YES.

This allows Doxygen to create pretty graphs and render them with dot.
Doxygen-ify header comments.

This is required by the LLVM coding stadards. See
<http://llvm.org/docs/CodingStandards.html#file-headers>.
[docs doxygen] Set STRIP_FROM_PATH.

This prevents the local path of the source tree from leaking into the
doxygen output. As a side effect, paths get shorter and easier to read
in e.g. include graphs.
Get rid of CRLF line endings.

These were tripping up git when building the gh-pages branch.
[docs] Nicer link to doxygen.