Error message enhancement in SshScpFile.getFileInfo

[farrault]

For a currently unknown reason, "ls -ld" through sudo connection always returns 0 on one of my target server, event if the file doesn't exist

In this case, SshScpFile.getFileInfo throws this errror :
"ls -ld /inexistent/file returned unparseable output: xxxx" (on my system xxxx is not empty, see #46 )

To ease diagnostic in such broken system, you should be more explicit, like :
"ls -ld /inexistent/file returned 0 but its output is unparseable : xxxx"

[hierynomus]

Thx! We'll have a look. Pull request is always welcome ;-)