Can not get codes by get_source.sh at Japanese environment.

[Yuji Kubota]

Hi all,
I wrote this report and patch at Hackergarten in JavaOne2014.

When I try to get source codes of jdk8 in Japanese environment,
get_source.sh can not parse the "hg -version" correctly.
So I can not get the source codes, because the result of "hg -version"
has japanese charcthers.

Mercurial use *.po files for i18n, so I set required LANGUAGE before
call hg commands.
Please review attached patch! :)

And thank hackergarten for many advices!
---
KUBOTA Yuji