Revert "use naturals with variable width as symbols"

This reverts commit 790dcf2c372a91d2780a20551c6e76c60ee934f6.
add self contained n-queens example
add standalone LPO example
set top argument to False
Merge branch 'usable-rules' of https://github.com/jwaldmann/co4 into usable-rules
cpf proof with >1 reductions (not working)
fix warnings in ghc-7.8
Merge branch 'master' into usable-rules

Conflicts:
	tc/CO4/Test/TermComp2014/Util.hs
fix cpf output
fix standalone termcomp2014
obey outputCNF flag
refactor argument filters
proper handling of usable rules (they are only considered inside redPairUrProc)