Port multiple selection property fix from 2.6 branch. Also undid a previous fix which prevented multiple select properties from being added TTW.

addressed, so I just improved encodeExpansion()'s compression behavior.

specifically set.

selection" properties better (ie. default to an empty list, not empty string)

- normalize whitespace

  it more readable
- remove unused instance variable

PageTemplateFile.__init__() does some weird magic.
Without this, the sniffer tests failed on Windows.

- modernize a type-check

- modernize several type-checks
- remove unused imports

referenced for too long.

case if we're aborting e.g. a transactional undo.

You never need an __del__ to close a file.  A file closes itself when
it is deallocated.

Don't give an object a magic __del__ attribute.  It won't work with
new-style classes, and it's obscure anyway.

(The "build" target used to be an in-place build, but someone changed
that.)

- remove unused imports
- misc. cleanup

- normalize whitespace

- avoid normalizing whitespace when using the default text when there is not
  a matching translation
- added support for explicit msgids in the i18n:attributes syntax

When loading a PageTemplateFile that's not XML, make sure it ends up
loaded in text mode. This was a problem for Windows.