This method replaces '//' with '/' to make the paths look nicer.
Originally it correctly skipped a leading '//' in a UNC path as the
comment says. However, commit "Removed extra variable initializations"
(2005-04-15) accidentally removed the "pos=1" initializer. It was then
incorrectly restored by commit "Added missing variable initialization"
(2005-04-15) as just "pos=0". Restore the proper initializer.
The test for this added by commit "better coverage" (2006-07-31)
included incorrect output for a sample UNC-like path. Fix it.
This converts the KWSys license to a pure 3-clause OSI-approved BSD
License. We drop the previous license clause requiring modified
versions to be plainly marked. We also update the KWSys copyright to
cover the full development time range.