BResources SetToImage docs: update variable name in retval (tiny)

Documentation updates for Storage Kit classes

* Added \since to each method and parameter.
* Whitespace cleanup.
* Some other minor cleanups and updates.

Set brief for desc of Path.h Query.h Resources.h and Statable.h

Move resources docs to Haiku Book

* Remove docs from Resources.cpp (leaving the brief description).
* Reformat Resources.h to style it like so many other header files.
* There is one not-entirely style based change. I renamed the outSize
parameter or the LoadResource method to _size as is our convention for out
parameters.

Documentation updates for Storage Kit classes

* Added \since to each method and parameter.
* Whitespace cleanup.
* Some other minor cleanups and updates.

Set brief for desc of Path.h Query.h Resources.h and Statable.h

Move resources docs to Haiku Book

* Remove docs from Resources.cpp (leaving the brief description).
* Reformat Resources.h to style it like so many other header files.
* There is one not-entirely style based change. I renamed the outSize
parameter or the LoadResource method to _size as is our convention for out
parameters.