Create a new temp table for style items to be inserted into history.

This is only to get a proper ROWNUM (not supported by SQLite) for the
select results.
Fix order of style items recorded into the style and when applied to image.
When apply a style to a duplicate make sure the collected images are updated.

Now that the collected images into the lighttable are stored separately
into a memory table, we want to ensure that this collection is properly
updated when applying a style to a duplicate. we were not doing this
and the duplicated image was not visible until some filters were changed.
usermanual: some clarifications
Italian translation updated
Merge branch 'fix-multi-prio-in-style'

* fix-multi-prio-in-style:
  Fix order of style items recorded into the style and when applied to image.
  Create a new temp table for style items to be inserted into history.
Merge pull request #334 from bartokk/master

Italian translation updated
lua : make all events synchronous again.

we will have another way to have async works.
lua: re-add the lua lock. it's needed after all...
lua : use a pointer as a unique id for tasks instead of an ID
lua : add lua support for webp

documentation has not been updated yet
Update French translation.
rawspeed: update to svn r605
rawspeed: Re-add some custom stuff in our copy
Make our code base more portable