Passing tests

See #737

It now uses wrapper/Plumed.h code. This required adding
an exception in the plumedcheck script to allow inclusion of that header.

The result is not just less code duplication but (a) type checking and
(b) exception re-throwing

Adding asmjit was leading C++ quality down to C,
since it brings in many alerts.

the energy was not correctly updated if the move was accepted

- matheval not needed
- fftw is already on by default

stack trace is fully parsed only when accessed with stack()
or when PLUMED_STACK_TRACE=yes

Make sure incorrect conversions trigger an exception