on QFileInfo to tell us that a file is not writable, but accept
that the attempt to save a file might actually fail (:-) ). This
solves the NT network domain issue without the insane slowness.

The stuff needs more work. We do not have any UI for failing save
operations when closing creator (other than it doesn't close). Bad.

Done with: mae

Done with: mae

Reviewed-by: Thorbjorn Lindeijer

Pointed out by Mathias Gumz.

bugfix for windows: trying to open files stored on network drives relied on QFileInfo::isWritable() without using the real filesystem checks

It is desirable to have removal of trailing whitespace as a separate
option to "tab cleanup". Clean Whitespace option without Clean
Indentation option will now only remove trailing whitespace on file save
and on Clean Whitespace requests. Clean Indentation option is set to
true by default to maintain backward compatibility.

Signed-off-by: Adam Majer <adamm@zombino.com>