Recognize Windows absolute urls. C:\, e:/, etc

Running curl during development cycle on a windows pc, can cause an annoying crash, if you try to load a curl module. toUrl function will return an invalid localDirectory/localDirectory/file, since it is unable to understand that a path that starts with C:\ or something like that is an absolute url. This improves the isAbsUrl function by updating the absUrl regex to include windows style absolute urls.