Issue #831134 by MegaChriz: fixed bug in upgrade script. Upgrading resulted in failures when long field names (> 11 characters) where used.

Issue #831134 by MegaChriz: Wrote an upgrade script from 6.x-1.x to 6.x-2.x. Some of the previous update functions were changed to fit the upgrade at best.

by MegaChriz: Fixed link to help page: this was leading to a non existing page when the core help module was disabled.

  - Added field types documentation in the README.txt.
  - Added help via hook_help().
  - Added validation for PHP fields: now is checked if PHP-code is enclosed in php tags.
  - Added validation for select fields: now is checked if the select field has an "empty" option (e.g. "Please select") when the field is marked as required.

by MegaChriz:
  - Little bugfix for select fields on order edit page: if there was no saved value or an empty value for that field, the select field no longer displays "Deleted option:".
  - Checked all strings for translatability and updated some of them.

By MegaChriz: Small fix in token values: empty values will no longer result in "n/a" being displayed.

  - Bugfix UC Addresses integration: do not add address fields to user
    register form if no address is required upon registration.
  - Bugfix: don't make fields from Extra Fields Pane required on order
    edit pages.
  - Other little fixes (code refactoring).
Issue #1042076 by mrfelton, MegaChriz:
  - Do not output field label with colon in theme functions if field
    label is empty.
Issue #1160556 by MegaChriz:
  - Changed behaviour of select fields. Options are now defined as
    safe_key|label instead of the opposite it was.
  - Made options labels translatable with i18n.
  - Added Views field handler for selection fields: in Views labels
    of option values are shown instead of the key.
  - Fix for select fields on order edit page: if the saved value
    isn't available anymore as an option (if for example that option
    has been deleted), the saved value is now added as an option, so
    the saved value won't be overwritten when editing the order.

Issue #1112254 by wjroes: Added i18nstring integration for field label and description.

  - Fixed exposed views filter for Extra Fields Pane selection fields
#907446 by MegaChriz:
  - Added 'Display options' feature.
by MegaChriz:
  - Added hooks documentation.

  - an extra row (':') is no longer added when chosen field type is
    constant or PHP constant.
  - removed theme function theme_uc_extra_fields_pane(), replaced by
    theme_uc_extra_fields_pane_checkout_pane(), which is added to the
    file 'checkout_pane.inc'.
  - various other fixes

  - an extra row (':') is no longer added when chosen field type is
    constant or PHP constant.
  - removed theme function theme_uc_extra_fields_pane(), replaced by
    theme_uc_extra_fields_pane_checkout_pane(), which is added to the
    file 'checkout_pane.inc'.
  - various other fixes

  - fixed a bug that caused a fatal PHP error during checkout because
    a file didn't got included.

  - moved non-hook functions to separate files to increase performance
  - changed API
#914806 by MegaChriz:
  - added views integration
#913852 by MegaChriz:
  - fixed 'saved addresses' drop down

  - moved address fields adding to 'Address fields'-page
  - changed admin interface
  - introduced common API function for field forms (add/edit/delete)
  - introduced API function to generate fields
  - an address field now comes in both panes by default
  - fixed 'my billing information is the same as my delivery information'
#831134 by panthar: added token support
#831134 by MegaChriz:
  - changed uc_extra_fields_values table completely
  - added support for extra address fields in token hooks
  - fixes in order handler function