I'm trying to split the source of an external I'm writing to more than
one .c files but I'm failing. I have two .h and two .c files, where one
pair includes all the Pd specific functions, line new() and setup(). In
the Makefile (pd-lib-builder), I include the following line:
```
common.sources = src/dense.c
```
This is the .c file where I want to include part of the code. The object
compiles. I even get some warnings about this dense.c file, but when I
try to load the object, Pd complains that it can't find certain
functions that are included in this dense.c file.