#219 (strip) encoder to remove prefix from C names

[anatoly techtonik]

The patch against latest SVN adds "strip" encoder that removes leading prefix from C names. Useful for wrapping C libraries that usually have all their functions prefixed. Prefixed function calls look ugly when wrapped into Python module with the same name, and hence this encoder.

[anatoly techtonik]

strip prefix encoder

[William Fulton]

Thanks, committed for swig-1.3.37.
Note that a general regular expression library would also provide the same functionality, but this patch provides a very common use case that is best met now before/if a reg exp library is added (of which I know of none that is forthcoming).