Utilities.pm: In Windows the separator for $ENV{'PATH'} is ';'
instead of ':', and '.exe' must be added for file test -x
to work. Gzip package for Windows don't provide "gunzip",
but "gzip -d" can fulfill the same role. Also added
double-quotes for executable paths with empty spaces.
Utilities.t: The '\' in Windows path for $file and $zfile
broke the qr{}, so changed them for '/', which also works.