enable to configure with older versions of autoconf

[nori0428]

#1158
(already closed)

configure.ac at master: AC_PREREQ(2.57)
This means that libuv is enable to configure with autoconf version 2.57 or newer.

But AS_CASE is enable to use autoconf 2.60 or newer version.And AS_CASE has a BUG until version 2.69.
So AC_PREREQ(2.69) might be more better solution.

If you can support older versions of autoconf, please check this patch.
Regards and great thanks for your very useful software.

[Nodejs-Jenkins]

Thank you for contributing this pull request! Here are a few pointers to make sure your submission will be considered for inclusion.

Commit nori0428/libuv@a503ff1 has the following error(s):

• Commit message must indicate the subsystem this commit changes

The following commiters were not found in the CLA:

• Norio Kobota

You can fix all these things without opening another issue.

Please see CONTRIBUTING.md for more information

[saghul]

Thanks @nori0428! I'll give it a shot on OSX 10.6, where autoconf is borked.

[nori0428]

I'm sorry. I forgot to write LICENCE.
An attached as_case.m4 file is a part of /usr/local/share/autoconf/m4sugar/m4sh.m4.
'Copyright (C) 2000-2012 Free Software Foundation, Inc.'

[saghul]

Hi @nori0428, I tested your patch with autoconf 2.63 (version that shipped with OSX 10.6) and it's working great!

Can you please sign the CLA (http://nodejs.org/cla.html) so I can merge your changes? Thanks!

[indutny]

@nori0428 ping ;)

[saghul]

Checked the CLA, it's signed. Landed in 1759781 Thanks!