UTF-8 BOM option (default=false)

Option to save with BOM or not ..all files where being saved with BOM, which is now set to false by default. BOM causes endless problems with other open-source projects, and apparently even with older IE versions.

Actually only MinifyFileWithSourceMap() was using BOM=false, everything else was using BOM=true

..double check. I simply applied the choice to anywhere new UTF8Encoding() was being called to be sure other file types (coffee ..) benefit from this too.