The conversion to Python3 added an eval() call which is wrong.
Fix the spelling in execute.
Fix labels in the tester gdb locking.
Check the debug-trace arguments.
Close#2642.
Installing PYO and PYC does not work so disable this. Move the
Python check to the top level and have a single place.
Fix the install paths a revert the 'from . import' changes. This
is resolved by installing into the correct paths.