- only supports code in strings, not files (should be easy to add)
- only the "exec XYZ in GLOBALS [,LOCALS]" form is supported, not the execution in the current namespace (would require a mapping representation of it)
- also includes an incomplete (3-args only) and untested implementation for the exec() function in Py3

more balancing needs to be done.

They're still in the source, but it makes the html less redundant and easier to read...