Check that if only the code of a PythonScript (_body) is different,
it will be identified as modified.

Installation of business template may change the encoding of a document to utf-8.
Nonetheless, export should preserve the original encoding.
This test creates a ZopePageTemplate with output_encoding of 'iso-8859-15'
and checks that while installed version becomes 'utf-8', when exported it
keeps the original one.

Only xml metadata should be exported in this case.
In the previous version the check of hasattr could pass
if attribute is defined as an attribute of the class and not of the instance,
causing also AttributeError later when the code tries to invoke delattr.

Also, restructure export. First try to delete property and then
export as separate file.

Test also added.

to the Portal Types for which the data
is exported separately to the meta-data.
Tests added to testBusinessTemplateTwoFileExport.py

TemplateTool: importAndReExportBusinessTemplatesFromPath renamed to importAndReExportBusinessTemplateListFromPath

BusinessTemplates: Allow export of files like Python Script, Web Page, Web Script etc. separately from the xml