loadProcess uses a generic string splitter

Added a placeholder test for loadProcess. Eventually this
placeholder test will check that loadProcess
correctly applies fixed width splitting.

Have temporarily modified loadProcess to allow test to avoid the
trap hack, throwing errors on any invalid rows. This will need to be
rolled back before branch is merged into master, and the test
must be modified to handle the trap hack.
add fixed length column splitting to API

A loadFixedLength API call exists now, which uses fixed width splitting.
The loadProcess test uses and checks the fixed width splitting.

We no longer work around the trap hack.
protect loadProcess by moving it out of the Load trait

This allows users to call loadProcess if they really want to, but
they will have to go around the official Maestro API to do so.