Update analyser to detect other complex tables

[Turnerj]

This is a general issue stub for detecting other types of tables rather than just heading/data pairs and cross tabulation.

Other types include:

• Complex cross tabulation (where it has one or more empty columns inbetween another cross tabulated piece of data)
• Plain tables (currently beyond the responsive resize, the code doesn't do a "breakmate" - a div-based HTML tree of the table data)

There are a couple of others that might be worth investigating too (eg. handling totals for cross tabulation)

[Turnerj]

Started to add advanced cross tabulation support (aka. complex cross tabulation) in commit 5ae69cdd3f3dec0caa9c4f384fc19524d2bb47a4.

With the code cleanup mostly complete for now, supporting more table types is the next priority.