Remove EmptyByDefaultListBox_asHTML in listbox and use generic customisation

This reverts commit eac0cc35.

gcc is "incompatible" from version to version in accepted parameters.

previous code is copied in erp5_trade_simulation_legacy business template for backward compatibility. we need to do the same thing on packing_list_workflow.

There is no rule to put install in /usr/bin.

As gcc 4.6.0 treats more warnings as errors, memcached compilation fails.
Solution took from original bug report for memcached.

Do not try to parse contents which are not XML with xml parser.

It's tested earlier in the same method.

self.getObject() is called right at the begining of this methd anyway, so
just keep & reuse it.

Instead, replace them with standard unicode "rempalcement char":
http://en.wikipedia.org/wiki/Replacement_character#Replacement_character

By Romain and Luke.

As slapos.recipe.erp5 depends on Zope2 in order to generate Zope2 aware
scripts reuse this dependency and import needed method instead of
rewriting it.