export_excellon
===============
```{function} export_excellon( CSX, filename, options )
```
Full definition:
```{code-block} matlab
export_excellon( CSX, filename, options )
```

Exports the geometry defined in CSX to filename as an excellon drill file.
Only cylinders will be considered for export.
The xy-plane is exported.

- CSX: CSX-object created by InitCSX()
- filename: export filename (e.g. '/tmp/export.gbr')
- options (optional): struct
  - .header: (string) add this to the header of the file
       comment line must have ';' as the very first character
  - .exclude: (cell array) ignore these CSX-properties
  - .include: (cell array) include only these CSX-properties
       if neither .exclude or .include is specified, process all properties

See also InitCSX 


-----------------------
author: Sebastian Held <sebastian.held@gmx.de>
26. Aug 2010: initial version