The virtual package declared by PROVIDES must not have the same name as the
variant declaring it, otherwise buildroot will fail with errors like:

    cp: '.../pkginfo/mosquitto.provides' and '.../pkginfo/mosquitto.provides' are the same file

In order to fix the above error, rename the existing "mosquitto" and
"libmosquitto" packages into "mosquitto-ssl" and "libmosquitto-ssl"
respectively.

Also substitute use of $(PKG_NAME) with literal "mosquitto" in
Package/* defines to improve readability of the Makefile.

Signed-off-by: Jo-Philipp Wich <jo@mein.io>

Many users of the SSL build of mosquitto need the passwd utility for
managing keys.

Fixes github issue #1909

Signed-off-by: Karl Palsson <karlp@remake.is>

Of particular note, this adds optional support for websockets. This
defaults to enabled, as it's the biggest new feature in this release.
A config item is provided to disable it for manual use.

Full release notes: http://mosquitto.org/2015/02/version-1-4-released/

This also remove some build workarounds that are no longer required for
newer versions of mosquitto.

Signed-off-by: Karl Palsson <karlp@remake.is>