Merge pull request #4 from Industriromantik/develop

Defined String lengths or switched to Text (MySQL support)
0.2.7.4
=======

* **Fix:** Fixed the following columns column type from String to Text:

    * Permissions.class_name
    * SimpleEntities.description
    * Links.full_path
    * Structures.custom_template
    * FilenameTemplates.path
    * FilenameTemplates.filename
    * Tickets.summary
    * Wiki.title
    * Wiki.content

  and specified a size for the following columns:

    * SimpleEntities.html_class -> String(32)
    * SimpleEntities.html_style -> String(32)
    * FilenameTemplates.target_entity_type -> String(32)

  to be compatible with MySQL.

* **Update:** It is now possible to create TimeLog instances for a Task with
  PREV status.
0.2.7.5
=======

* **Fix:** Fixed Task parent/child relationship, previously setting the parent
  of a task to None was cascading a delete operation due to the
  "all, delete-orphan" setting of the Task parent/child relationship, this is
  updated to be "all, delete" and it is now safe to set the parent to None
  without causing the task to be deleted.
0.2.7.6
=======

* **Update:** Removed ``TimeLog._expand_task_schedule_timing()`` method which
  was automatically adjusting the ``schedule_timing`` and ``schedule_unit`` of
  a Task to total duration of the TimeLogs of that particular task, thus
  increasing the schedule info with the entered time logs.

  But it was setting the ``schedule_timing`` to 0 in some certain cases and it
  was unnecessary because the main purpose of this method was to prevent
  TaskJuggler to raise any errors related to the inconsistencies between the
  schedule values and the duration of TimeLogs and TaskJuggler has never given
  a real error about that situation.
fixed ``db.DBSession`` call examples in design.rst
fixed ``Status`` class documentation
removed unnecessary parameter in ``stalker.models.walk_hierarchy()`` docstring
started implementing ``create_alembic_table()`` to ``stalker.db`` module
Merge branch 'develop' of https://github.com/Industriromantik/stalker into Industriromantik-develop
updated User and Project classes, tests of them and the new alembic revision related to the new Client class
Merge branch 'Industriromantik-develop' into develop