#1 support cygwin directories

[Mark Streich]

Running jlint under cygwin fails because the program
seems unable to handle cygwin/unix style directories
using the / character.

Running from within the /tmp directory:

./jlint.exe +all foo.class

works.

But specifying the directory where the file resides:

./jlint.exe +all /tmp/foo.class

fails with:

Failed to open file '/tmp/foo.class'