add a foreach and select function to conditionals

select returns a single result for a selection
foreach is similar to forall but iterates over all values (see List.*)
first draft of a differential testing framework for the lexer
differential testing framework for the lexer
jcpp version of differential testing against cpp
improve output
removed old test infrastructure now replaced by differential testing against cpp

the old textual specifications were imprecise and adhoc and often not well maintained
now it compares the output of the lexers against CPP in all configurations
which is precise. therefor the old test are no longer needed
remove quotes from cpp command line
log messages distinguish now xtc and jcpp
update to new travis infrastructure