Bug: make clean in wrspice deletes needed files

Hi,

There seems to be a bug in the system of makefiles.  Typing:

```
cd wrspice
make clean
make
```

leads to a number of errors.  It seems that 'make clean' is incorrectly deleting wrspice/bin/*.cc.  The build using 'make' works again once these *.cc files are recreated using 'git restore'.