Use "integer" and "float" rather than "long" and "double" in messages to users.

Error messages mentioning "long" and "double" are confusing to users, as these are not the names used for the types in the manual or userland functions; they should refer to "integer" and "float", respectively. 

This PR updates all the appropriate messages, and all PHPT tests expecting them (the tests make up the bulk of the changes).

I would consider this a bug fix, although there may be tools out there relying on the current wording. In particular, I noticed that echoing a whole class using reflection used the "wrong" terms (see changes to ext/reflection/tests/bug29986.phpt).

I've never submitted a pull request before, and made this change a while ago and then forgot about it, so let me know if I've not followed the correct process.