[JENKINS 18643] Make tests run on Windows (line break character, query parameters for file schema)

I have troubles in testing resgessions on Windows, for there are tests that always fails on Windows.
These commits do following changes to jenkins-test-harness, which make some of those tests succeed also on Windows. 

* Use environment-dependent line break characters instead of LF (0x0a). 
    * On Windows, CR LF (0x0d0x0a) is used instead of LF.
* Run local HTTP server when testing `UpdateSite` behaviour.
    * On Windows, query parameters with a file schema (file://.....?param=value) does not work.