Generalize Constitution.js to recognize generic legislation text

[aahilario]

The JavaScript program in constitutions.js is used to apply presentation elements (anchors and links, and human-readable TOC, table of contents) to the Constitution, structured as a series of HTML TABLEs. This script can be generalized to handle House Bills and Republic acts, if care is taken to apply correct outline-level presentation at run-time (during document rendering, after the document.onload event has been triggered by the browser).