Replace `extractFunctionFromError`

Instead of wading through the stack trace in case of an error,
we can just query for the function name...
Convert `figureVisible` directly to on/off boolean
Move some functions around
Runtests: ignore some tests (mechanism)

Mechanism to ignore some tests.
None are ignored currently.
Implement basic hash tables

Currently, only a single file is supported per test suite
Bugfix: close in Octave
MD5 checksums for ACID

Computed with Octave 3.8.0 on OS X