Various packages included vulnerable parsers generated by "flex".

This update provides a fixed "flex" package and also rebuilds of packages
that might have security issues caused by the auto generated code.

Flex itself was updated to fix a buffer overflow in the generated scanner
(bsc#990856, CVE-2016-6354)

Packages that were rebuilt with the fixed flex:
- at
- libbonobo
- netpbm
- openslp
- sgmltool
- virtuoso

Some more packages might also need to be rebuild to receive a new flex parser, but will be released later.

This update was imported from the SUSE:SLE-12:Update update project.