Add wchar conversion on non-Windows.
Merge pull request #244 from unknownbrackets/utf8

Add wchar conversion on non-Windows
stringutil: Add early-exit case to ReplaceAll

If both 'replaceands' are the same, the result string can just be returned.
Merge pull request #245 from lioncash/earlyexit

stringutil: Add early-exit case to ReplaceAll
Merge https://github.com/hrydgard/native