more compact print function for BDDs

avoids explosion to DNF, but potentially still not optimal
change license GPL v3 -> LGPL v3

after internal discussion with all contributors
update parameter list with genpages.sh
add paper link to variational programming paper
Merge branch 'master' into integervulnerabilities
refactor option infrastructure

all option parsing goes on in the frontend project now. all other
projects only have an interface with the options they can process

the frontend binds all those interfaces together into a command-line
interface
introduce options for the type system and analysis
guard security warnings by commandline options
refined option printing once more
extra command-line option to decide whether to rewrite line numbers

note: default behavior changes!
also fixes that after rewritings tokens always refer to the output file
TypeError -> TypeChefError extracted into separate project

allows different projects to use the same error reporting facilities
use severityExtra for analysis errors
fix scaffolding for Integer vulnerability tests

these checks are inactive by default and tests need to activate them