Document estmaster with Hypy

[Cory Dodt]

Document the interaction between Hypy and estmaster. This requires first investigating the interaction between Hypy and estmaster. It's probably no worse than using estmaster with any other kind of Hyper Estraier index. Give examples of a few common uses and solutions.

Spinoff from bug 321683.

"""
Hypy doesn't do anything unusual with indexes, or even really interact
with them on that level - all access to the database, including
creation, is done through Hyper Estraier APIs. So yeah, it should
work, but I haven't tried it. However, Hypy itself doesn't yet
support any of that federated search stuff, so an application that
accessed an index through Hypy would not, e.g., be able to eclipse
results; but any *other* application that accessed the same index
would be able to use it that way with no problems.
"""

* Add documentation to the doc/ directory in RST format. Maybe just add another section to examples.txt.

* Unless using examples.txt (in which case no change is needed), also update 'make website'.