proftpd: add from meta-baryon

This was originally from OE-Classic. Improvements over the OE-Classic
recipe for reference:

* Update to 1.3.4b
* Add workaround for proftpd host IP resolution
* Add initscript, borrowed from Debian with some modifications for
  compatibility and handling for hardcoded paths
* Use autotools.bbclass and remove unnecessary configure options
* PARALLEL_MAKE = "" is no longer needed, the bug was fixed in 1.3.3c
* Set SUMMARY (which sets DESCRIPTION) and base it on the short
  description from the website
* Use useradd.bbclass to add ftp user/group
* Add HOMEPAGE
* Add/fix description in some patches and improve recipe indentation
* Make LICENSE more accurate
* Add LIC_FILES_CHKSUM

Some of this work was done by Dexuan Cui <dexuan.cui@intel.com> and
Kevin Strasser <kevin.strasser@linux.intel.com>.

Signed-off-by: Paul Eggleton <paul.eggleton@linux.intel.com>