Improve compiled code

[gjmcn]

The code for the Zap operators used in a file is included in the file — either inline or as a method of the local _z_ object. There are various problems with this approach and its implementation:

• Some operators require a significant amount of code, so potentially repeating the code in multiple files is bad.

• The code for _z_ methods is not source mapped. If a _z_ method throws, the error is reported as originating from the first line. The true source of the error from the user's perspective (i.e. where the _z_ method was called from) is further down the call stack.