Syntax error: add missing function keyword for function expressions
Syntax error: add missing comma in list of arguments
Revert "Syntax error: add missing function keyword for function expressions"

Apparently, these are not function declarations, but calls to the
onChange functions of obj_src and obj_trg, expected to be declared beforehand.

This reverts commit d6782acd40c189b977ca8624a43261c09a9f3028.
Translate section 'API 4'

I also inserted a link to Wikipedia for 'human readable'.