* cygpath.cc (main): Add option l to support conversion to
Windows long file names. Refactured code for capital options.
Support of options from file for capital options.
(dowin): New function. Refactured from main.
(doit): Call long path conversion.
(get_long_name): New function.
(get_long_paths): New function.
(get_long_path_name_w32impl): New function. Reimplementation
of Windows API function GetLongPathName (only 98/Me/2000/XP or
higher).
(get_short_name): Call GetShortPathName only once.
(get_short_paths): Fix calculating buffer size.
* utils.sgml: Update cygpath section for l option.