fixes #117

undo problematic optimisation that compiled plugins wrongly
contextual value now use cascading names

meta "name" contains the original name
dynamic+static lookup possible
add some more tests
convert to gtest part 1
migrate cpp11 tests to gtest
use all generators for all shell tests
switch to new override/fallback syntax
start to use utility
gen compiles again

reduced a lot of code duplication
added util functions
extended gen tool to generate temporary python source
use classes for support: dynamic binding