Moved used strict to be invoked in the context of MiniProfiler

By including "use strict" in the top of the file it is causing strict mode to be invoked globally for the file. This isn't a problem if it is just one file, but if it is combined into another file it would invoke strict mode for that.
Merge pull request #3 from Kevnz/patch-1

Moved used strict to be invoked in the context of MiniProfiler