fswebcam: new package

[Thomas:
 - use the autotools-package infrastructure, since the package uses an
   autoconf configure script.
 - remove uninstall and clean commands since those are no longer
   supported by Buildroot.
 - rewrap the help text.
 - order alphabetically the package in package/Config.in]

Signed-off-by: Lucas De Marchi <lucas.de.marchi@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>