No TTY should not imply batch mode

Commit 6ea48cbb introduced an isatty() check on stdin and
automatically sets batch mode if we're not attached to a TTY.

Although the logic of this seems simple enough the combination of
this and commit 4b46e04 breaks valid uses that have worked since
sos-1.x, e.g.:

Traceback (most recent call last):
  File "/usr/sbin/sosreport", line 23, in <module>
    main(sys.argv[1:])
  File "/usr/lib/python2.7/site-packages/sos/sosreport.py", line 1171, in main
    sos.execute()
  File "/usr/lib/python2.7/site-packages/sos/sosreport.py", line 1133, in execute
    self._setup_logging()
  File "/usr/lib/python2.7/site-packages/sos/sosreport.py", line 630, in _setup_logging
    self.opts.batch = True
  File "/usr/lib/python2.7/site-packages/sos/sosreport.py", line 324, in batch
    self._check_options_initialized()
  File "/usr/lib/python2.7/site-packages/sos/sosreport.py", line 229, in _check_options_initialized
    + "from command line")
ValueError: SoSOptions object already initialized from command line

Given the actual semantics of --batch (do not prompt for or read
user input from stdin) there is no need to enable it if stdin is
a pipe or other non-TTY file descriptor.

Signed-off-by: Bryn M. Reeves <bmr@redhat.com>
Do not exit on interactive mode read exceptions

Currently the default policy object will exit without logging any
errors if an exception (e.g. EOF while reading line) is caught
during reads for interactive mode prompts.

Instead re-set the report name to a sane value (localname) and
attempt to continue.

Signed-off-by: Bryn M. Reeves <bmr@redhat.com>