LazUtils: in ResolveDots() convert '/'to '\' on Windows.
This allows for better removing of double path delimiters.
(WinApi accepts '//' and treats it as '\' , bot not so for '/\')


git-svn-id: http://svn.freepascal.org/svn/lazarus/trunk@42599 4005530d-fff6-0310-9dd1-cebe43e6787f