Fixing bug where the file handle is not closed properly because the parentheses are left off the call, telling Python to return a method but not call the method.

Without this fix you have to enter your vault password before you realize
that you forgot to pass in the filename.  This commit checks that an
filename argument was at least passed on the command line.

Also add a unit test for vaulteditor to verify 1.0 passwords with newline chars.