#4 Handle TODO: descriptive text

[Jan Schlamelcher]

The code generator shall handle occurences of TODO: <some-descriptive-text> in the source XML documents by:
1. Emiting a warning during code generation, preferably giving the file name and line number (and column) of the occurence and the descriptive text.
2. Highlight it in the generated artifacts such that it becomes clear during the review process.</some-descriptive-text>