First pass at "bulk loader" API -- at the moment loading is only supported at
the REPL (cmd-line interface coming soon).

 - Read tsv/csv format

 - matrix-like

 - S-Expression - work in progress

Exceptions and errors handlers live in their on module.

Added `pycall` -- a more convenient way to do `eval` and `mod`
()
added repl data loading example.
merge