Update installation/troubleshooting.html
Translated mongo docs.
Update CREDITS.md
Update classes/agent/config.html
Merge pull request #148 from yoshiakist/patch-2

Update installation/troubleshooting.html
Merge pull request #149 from inouet/1.5/develop_japanese

Translated mongo docs.
Merge pull request #150 from yoshiakist/patch-3

Update CREDITS.md