Issue #1214616: Improved translation sets to keep track of related ones when moving items from one to another.

Issue #1192332: Fixed Incorrect message on wrong Block translation. Other format handling issues for translation form.

Fixed issues with setting string value and language code not passed around. Added per-textgroup hidden debugging option

Improved field translations and string handling. String objects are passed around instead of complex data arrays.

Fixed issues with previous commits. Introduced some more overridable functions for object translation.

Issue #1185644: API improvements. Added some internal caching (properties) in i18n_string_object_wrapper. Added some more easily overridable method translate_properties().

Issue #1185644: API improvements. Added i18n_string_object() to handle strings. Adding better caching for strings.

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. Improved format access checking. Renamed i18n_string_object to i18n_string_object_wrapper

Issue #1185644: API improvements. Simplified path handling for string translation. Not needed anymore i18n_taxonomy_vocabulary class.

Issue #1067618: Updating to work with l10n_client. Added some API functions to enforce permissions and formats.

Issue #671360 by dereine: switch default option for messages to not be printed with i18n_string; usability fix

Issue #1114602 by Gábor Hojtsy, yoroy: improve usability of i18n_string based modules dramatically by providing an API to expose a translation tab on objects
Reference implementation of that on blocks.