Use argparse for find-untranslated.

This replaces getopt.
I tried getting the complete script into an argparse parser, but failed,
because starting the command line arguments with a command and then options
and more positional arguments seems unsupported by argparse.
Tried docopt as well, but that tripped up.
Add optional source of zope.tal for use with mr.developer.

I used this to investigate a bug in zope.tal.
Pin versions. Use ztk 1.1.6.
Fresh http://downloads.buildout.org/1/bootstrap.py
Add argparse parser for rebuild-pot command.
Add argparse parser for merge command.

Incidentally fix an error where the --merge option would be used as value for the --merge2 option as well.
if that option itself was unused.
Add argparse parser for sync command.
Setup parser for find-untranslated the same way as the others.
Add argparse parser for filter command.
Refactor filter_parser into two_file_parser.

The admix and trmerge commands also need two files.
Add argparse parser for admix command.
Add argparse parser for trmerge command.
Add argparse parser for list command.
Fix list command for locales structure.
Clarify list command a bit more.
Replace deprecated testcase method aliases.
Add options --wrap, --no-wrap and --width=NUMBER.

Use these to determine whether long lines are wrapped and at which width.
Default width is 79.
By default we do NOT wrap, because we have never wrapped before.
This may change in the future, so if you *really* want to be sure to not wrap
when using a future i18ndude version, you can add --no-wrap now.

Note that we no longer read the PO_MAX_WIDTH environment variable,
which we did in an earlier version of this wrapping feature.
See https://github.com/collective/i18ndude/issues/3
Refactor script to use one main parser plus sub parsers.
Call parse_wrapping_arguments in only one spot.
Do not print the language here.