Changes from 3.4.3 to 3.4.4

*Kernel:
- Added support for the template variable 'persistent_variable', which can be used to communicate between
  content templates and other templates, even though content caching is on. It can be set for example with
  {set scope=global persistent_variable=42} and fetched with
  {$module_result.content_info.persistent_variable}

*Bugfixes:
- Fixed bug: Broken datatype
  http://ez.no/community/bug_reports/broken_datatype.
  (Merged from 3.3, rev. 9321)
- Fixed bug with identifier datatype
  http://ez.no/community/bug_reports/identifier_datatype
- Fixed bug:
  http://ez.no/community/bug_reports/fatal_error_in_ezpackagetype_php
  http://ez.no/community/bug_reports/look_feel_fatal_error_ezpackagetype_php_line_165
  http://ez.no/community/bug_reports/setup_look_feel_appearance_dissappeared
  These three are the same bug. Symptoms: When editing "Look and feel" in admin, you get a
  "fatal error" in kernel/classes/datatypes/ezpackage/ezpackagetype.php on line 165, or
  the "Appearance" thumbnails and radiobuttons disappears from the page. The bug also causes
  a database corruption. To fix it, edit the "Template look" class and store it without
  changing anything.
- Fixed bug with class editing which caused objects to get duplicate attributes.
  http://ez.no/community/bug_reports/edit_class_issue_in_3_4_3
- Fixed bug: No customer name when using ezdefault shopaccount.
  http://ez.no/community/bug_reports/no_customer_name_when_using_ezdefault_shopaccount
- Fixed bug of possible fatal error when viewing url object link.
  http://ez.no/community/bug_reports/3_5beta_fatal_error_ezurlobjectlink_php

*Library:

eZDebug:
- Fixed output of arrays and objects to use PHP function var_export if it is
  available.
  (Merged from stable/3.3 (3.3-7) rev. 9331)

eZTemplate:
- Added scope support to the "set" template function. Scope can be global, root or relative (default).
  Also added unit tests for this.
