redland: add unixodbc dependency

unixODBC provides `sql.h`

Closes #25164.
Closes #25185.

Signed-off-by: Adam Vandenberg <flangy@gmail.com>
povray 3.7.0.0

Closes #24373.
Closes #23612.
Closes #24326.

Signed-off-by: Adam Vandenberg <flangy@gmail.com>
googlecl 0.9.14 (new formula)

Closes #24643.
Closes #25166.
googlecl: only wrap single file.
googlecl: add (crap) test.
duplicity: wrap with PYTHONPATH.

Closes #24062.
PythonDependency: massive refactoring.

Kill PythonHelper and cut everything out of PythonDependency beyond
setting up PYTHONPATH and supporting the existing DSL without changes.
Caveats: add automatic Python caveats.
Add helpers to wrap bin files with PYTHONPATH set.