Remove explicit template instantiation in headers

[En-En-Code]

Explicit template instantiations expect a definition, which is only found outsize of the evaluate.h header file, thus causing a compile error.

(Also, the unused TT functions are warnings made errors by -Werror, although I expect those are intended to be used at some point).

[jonathanmcdermid]

Sorry, I missed this MR. I think I've fixed the problem already.