Fixed: %language in menu not mapping to anything, replaced by %i18n_language and added object loader.

Issue #1185644: API improvements. Reordered functions. Improved object translation with some static caching. Using object translation for i18n_contact.

Issue #1185644: API improvements. Added hook_i18n_string_objects() for a module to return translatable objects, replacing string_list(). Added 'list callback' for i18n object metadata.

Issue #1185644: API improvements. Renamed 'contact' object to 'contact_category' for consistency and to prevent future clashes

Issue #1167126 by Gábor Hojtsy: implement hook_i18n_object_info() in i18n_contact.module so we can rely on i18n_string generating stock translation forms for us

Followup to #1155156 by Gábor Hojtsy: redirect the user back to the translation page, when they save a translation of an object

Issue #1155218 by berdir, Jose Reyero, Gábor Hojtsy: i18n_string_remove_string() does not exist, i18n_string_remove() does

Issue #1155156 by Gábor Hojtsy: add support for contact module translation; also apply the new i18nstrings translation tab concept