In Python, sys.exit() function can also take an object other
than an integer.

If an integer is given to the argument, Python exits with the return
code of it.  If a non-integer argument is given, Python outputs it
to stderr and exits with the return code of 1.

That means,

    print >> sys.stderr, "Blah Blah"
    sys.exit(1)

is equivalent to

    sys.exit("Blah Blah")

The latter is a useful shorthand.

Note:
Some error messages in Buildman and Patman were output to stdout.
But they should go to stderr.  They are also fixed by this commit.
This is a nice side effect.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Acked-by: Simon Glass <sjg@chromium.org>

This tool helps to create/update the mailmap file.

It runs 'git shortlog' internally and searches differently spelled author
names which share the same email address. The author name with the most
commits is asuumed to be a canonical real name. If the number of commits
from the cananonical name is equal to or greater than 'MIN_COMMITS' (=50),
the entry for the cananical name will be output. ('MIN_COMMITS' is used
here because we do not want to create a fat mailmap by adding every author
with only a few commits.)

If there exists a mailmap file specified by the mailmap.file configuration
options or '.mailmap' at the toplevel of the repository, it is used as
a base file.

The base file and the newly added entries are merged together and sorted
alphabetically (but the comment block is kept untouched), and then printed
to standard output.

 Usage
 -----

  scripts/mailmapper

prints the mailmapping to standard output.

  scripts/mailmapper > tmp; mv tmp .mailmap

will be useful for updating '.mailmap' file.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>