Initial version of ZIP file reading/writing modules.
These are below the org.conman.zip module.
Bug fix---forgotten "do" keyword.
Bug fix---reference functions used in code.
Install the zip stuff.
Rename files.
Bug fix---forgot to include setmetatable
Bug fixes---lots of bug fixes.

* change parameter name from zip to zf
* cached local copies of functions used
* parse iattr field
We can now write ZIP files.

Okay, the extra fields of a file aren't supported quite yet, but if we ignore
that for now, we can write a ZIP file.
Bug fix---don't subtract one from the month.
Code to write the data descriptor segment.
Feature---leave file at central directory when reading the EOCD.

I've been bitten too many times for not resetting the file position to
the central directory to NOT do this.
Change result of extra data

If there's no function for handling an extra data, set it to something
that's user visible (for now).
Convert org.conman.syslog for Lua 5.1 or higher.