Make IPA/orthography tables optional

[jcrippen]

Right now every table comes in two flavours: orthography and IPA. This literally doubles the size of the document. Language learners are probably less interested in the IPA representations and so could benefit from a document with just orthography tables. Likewise, phonologists may be less interested in the orthography representations and could benefit from a document with just IPA tables.

Explore the various LaTeX tools for conditional compilation. We would want a flag that turns on one or the other or both. Some problems:

• Currently each page contains a single pair of tables. A single table per page wastes a lot of space, but there is an uneven number of tables per subsection: |{1SG, 1PL, 2SG, 2PL, 4H}| = 5.
• A few tables are very large so that pairs are wrapped in a single {table} environment to keep them on the same page rather than separate {table} environments for each table.