A potential fix for windows only undefined references for functions added while examining  #45
I added MEZZ_LIB to Now(), NowResolution() and Scoped_Timer. As a potential fix to #48. I think the last undefine references I fixed were the definitions to go with the prototypes, I think this one was those definitions not being found because they are were in a different compilation unit and not being found because they are not being exported. Just a guess, but maybe. Mako may have already ruled this out by adding these MEZZ_LIB attributes, but he seemed to indicate he only added it to the ScopedTimer class.