ec31a_patch:

Registered E programmers can use this patch program to obtain the registered
version of v3.1a. Simply make sure EC v3.0a resides in the current dir (with
the name 'ec30a', then run the patch. This will produce 'ec31a'.

Note that from v3.1a on, EC v3.1a will be the base for future patches.

Wouter