The lambdas add1 and add2 used the Vector copy-constructor when
capturing x, which made a deep copy.

TNL is not supposed to have any external dependencies, so an empty
config file is useless. If some marginal parts of the project (such as
code for image processing) need to depend on some non-standard library,
they should be split into a separate module/project so that the
dependencies can be properly specified.

For now, the macros are specified as compiler parameters. Client
software using the affected headers will have to do the same.

This allows int-vectors to be multiplied by float-scalars, producing
accurate int values (e.g. 4.2 * 10 == 42).

Now that error handling is done via exceptions, the return value is free
for more sensible things.

And of course our implementation is faster ;-)

- separate data types for input arrays of binary operations
  (necessary for the equality comparison of two arrays of different
  type)
- added separate template parameter for ResultType, which defaults to
  the RealType
  (the goal is to allow sum of bool vectors into int instead of bool)