In particular, protect the sysdb-data-to-lisp routine, that calls into
CFFI and character decodings, with a restart-case allowing the calling
code to just ignore errors on a particular column by skipping it and
using nil instead (or something else if needed).
Converting the table definitions (with type casting) seems to work. Also
did experiment a little with actuallt fetching some data... and had to
edit the cl-mssql driver, which is temporarily monkey patched.
The metabang-bind lib offers a nice bind macro that solves the problem
of ignoring bindings in destructuring-bind, and allows a let* approach
to nested destructuring (wven when mixed with let declarations).
Using that lib (that we already indirectly depend on anyway) simplifies
the parser code substantially.
