1) The function raw_input() sends output to stderr instead of stdout.
User prompts should be sent to stdout.
2) attack/wps: Fix printed message
3) attack/all: Change comment to better reflect return value meaning

Signed-off-by: Radu Nicolau <radunicolau102@gmail.com>

* `--infinite/-inf` argument activates the infinite attack mode.
  In this attack mode Wifite will enter a scan for <scan_time>
  and after that timer expires it will attack all nearby targets
  Infinite attack mode will respect all target and attack
  restrictions (-E, -b, --pmkid, etc.)

* `scan_time` is configurable by using the pillage (-p) parameter

* Stop the attack by sending SIGINT(Ctrl+C) while scanning for
  targets. The user will be prompted to choose between starting
  attacking targets or exit.

Signed-off-by: Radu Nicolau <radunicolau102@gmail.com>

The issue was that sending Ctrl+C would not be caught by the
try-except clause inside the scanner if the keyboard interrupt
was sent while inside inner try-except blocks. This would
result in airodump crashing and the Scanner.find_targets()
function returning, instead of prompting the user with the
choice to stop the attack.
This could be the possible cause for issue derv82#123

TODO: catch specific exceptions where possible

Signed-off-by: Radu Nicolau <radunicolau102@gmail.com>

* Removed exception in case target list is empty.

Normal scan mode will not be affected as it will
try to attack an empty list. The reason I removed
the exception is because in infinite attack mode it
is possible to press Ctrl+C too fast, resulting in 0
targets, yet it is not an error.

* Added error messsage in case airodump crashes.

The output will be the exit status code and the command
which was ran. Because airodump also prints to stderr
the useful output, we cannot realiably print error
messages from airodump.

* Added chipset/driver information link

Despite the fact that the link says the information hasn't
been updated, edits are still being made and the existing
chipsets will not change their specs. Coupled with driver
information, this link seems very useful for self debugging.

Signed-off-by: Radu Nicolau <radunicolau102@gmail.com>

Only display and attack APs that had at least <power> during the
current scan.

Because the power is not very stable it was possible for a target
to drop below the power level and be deleted from the target list.
This would in turn cause the updated targets not to overwrite the
existing list, which would cause wifite to output an unnecessary
amount of lines. The workaround is to compare the maximum amount
of power an AP had.

Signed-off-by: Radu Nicolau <radunicolau102@gmail.com>

… parameter)

Signed-off-by: Radu Nicolau <radunicolau102@gmail.com>