cleanup library headers
cleanup doc-strings
update authorship information

The copyright notices have not been updated in a very long time.  By now
so many people have contributed that it is not feasible anymore to have
a Copyright line in `magit.el' for everyone.  Now only people who have
made a fair amount of contributions are listed there.  These lines are
sorted by appearance.

Right below the now shorter Copyright list is a new link to the list of
all contributors on github.

The header keyword "Original Author" is replaced by just "Author",
that's how it is commonly done.  All keywords no longer contain
whitespace, but use a dash instead.

Both Phil Jackson and Peter J Weisberg are now listed as former
maintainers.  Peter has been removed from the list of active maintainers
as he hasn't done much lately.  Nicolas Dudebout and I are added to the
list active maintainers.  That list is sorted by activity.

Appropriate Copyright lines and Author keywords are added to files
besides `magit.el' (partly this is done in an earlier commit).

In `magit-svn.el' and `magit-blame.el' several people have already been
listed that have not made a single commit to those file.  I assume this
is because these files have been ported from other packages and therefor
did not remove anyone.

I have added myself as Author of `magit-wip.el' even though Ryan
C. Thompson wrote the first version, because his version was barely
usable.

If you are unhappy about a change please contact me.
remove bin/authors.pl and bin/mk_rel.bash

`bin/authors.pl' isn't useful anymore since we stopped having a
Copyright line for everyone who ever changed anything.

I am preparing to create a release but cannot see myself using
`bin/mk_rel.bash`, so I am removing that too.
move contrib/magit-{classic-theme,simple-keys}.el to separate repositories

I have created separate repositories inside the Magit organisation for
these files:

  https://github.com/magit/magit-classic-theme
  https://github.com/magit/magit-simple-keys

I don't think these files belong inside Magit proper.  Unlike
`magit-inotify.el' which is inside `contrib/' in the `master' branch
these files do not add experimental functionality which should not be
installed by default yet.  (`magit-inotify.el` depends on unrelease
Emacs-24.4).  Instead they change Magit's behaviour/looks in a way not
intended by the maintainers.

That is fine, and I think hosting the new repositories in the Magit
Github organisation is a good compromize.  Doing so has advantages for
both the people who want to use these libraries (provided my advice
about creating Elpa packages is followed) as well as me who does not
want them to complicate the build process.

Previously there was `make install_contrib' which installed both files
as well as the shell script `magit'.  I don't think many people use all
three files, so having one target to install them all makes little
sense.  I don't want to add individual targets for these files.

While it was previously possible to install these files using `make'
users who use Elpa to install Magit (and I hope most do so by now) did
not get the stuff in `contrib/' anyway.  Therefor the authors of these
libraries should add packages to Melpa and/or Marmalade if they want to
make them easily installable.

It is okay that there no longer is a target to install the shell script;
we would have to guess where on $PATH the user wants it, and would be
wrong in many cases.  It is better if users copy/move/link the script
themself.
move script contrib/magit to bin/magit

This should make it more obvious to people who run Magit directly from
the git repository that they can add this directory to $PATH.

Until recently `bin/` contained maintenance scripts.  I hope we won't
have to add similar scripts in the future; it would be possible to do
these things in the `Makefile' instead.