add an assertion to guide proof
coarsen assigns clauses (without real effect)
add -Wconversion option
add sharper precondition to allow safe conversion

from unsigned int to int
add bibtex entry for Kim's Diplomarbeit
Merge branch 'master' of github.com:jensgerlach/validation into jensgerlach-master

Conflicts:
	Reports/D4.2/D4.2.2-VV-Implementation/D4.2.2.pdf
add again
Merge branch 'jensgerlach-master'