It converts the number to "canonical" form removing insignificant digits,
leading zerroes and spaces what guarantees to fit a fixed size buffer and
does not changes result of strtod.
Review URL: http://codereview.chromium.org/1216005

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4282 ce2b1a6d-e550-0410-aec6-3dcde31c8c00