Removed unneeded comments

The first one is already on the documentation of
atk_implementor_ref_accessible.

Second one basic glib usage. If needed it should be placed
at documentation and not as a big comment on the main atk
object header.
Refactor tests directory

Each test suite is no longer a loadable module.
Split testrelation into testrelation and testrole.
tests: execute all role tests, doesn't matter if one fails
Use generated enum type for AtkRole to get the role name

Simplifies adding a new role (so less error prone) as with
this change a new role just needs to be added to the enum.

The specific role name is generated from the enum. For example:
ATK_ROLE_PUSH_BUTTON would create "push button"

It is also possible to specify the name. For example:
 ATK_ROLE_ACCEL_LABEL,      /*<nick=accelerator-label>*/
 would create "accelerator label"

Notice the '-'. At the enum it is needed to use it. Internally
all the names are compacted and maintained in one array (that
now also includes the extra role names).

https://bugzilla.gnome.org/show_bug.cgi?id=705290
Drop use of ATK_DISABLE_DEPRECATED guards in atk

Equivalent to gtk commit a78ab0cfa1d5e5e15d505bce0761a00708400ce3
Deprecate AtkObject::focus-event signal and all related methods

From now on, state-changed:focused is the only focus related signal
to use. All the tracking methods (on both AtkUtil and AtkComponent)
are also deprecated.

https://bugzilla.gnome.org/show_bug.cgi?id=649575
doc: removing several .sgml files and fixing gtk-doc warnings

The static documentation of those .sgml (so the reason of
tracking those objects) where moved to the source files.

Some other stuff was changed in order to prevent gtk-doc warnings
(like replacing "Returns blah" for the correct "Returns: blah")

https://bugzilla.gnome.org/show_bug.cgi?id=684665
Deprecate 'text-changed' signal

In favour of 'text-insert' and 'text-remove'

https://bugzilla.gnome.org/show_bug.cgi?id=653291
doc: little update on 'text-insert' and 'text-remove' documentation

https://bugzilla.gnome.org/show_bug.cgi?id=684705
docs: Add documentation for AtkRectangle

https://bugzilla.gnome.org/show_bug.cgi?id=491998
atkhyperlink: deprecate 'link-selected' property

As the property is deprecated, atk_hyperlink_is_selected_link is not
anymore used to get its value.

This closes bug bgo#573539
docs: stop tracking not needed .sgml file
Implement atk_text_get_string_at_offset() and deprecate old API

https://bugzilla.gnome.org/show_bug.cgi?id=705580
atktext: remove 'text-update' signal

That signal was created with wrong parameters, it is not used
at all, and it is not clear if it is needed. So removing until
someone brings the topic again, with a valid reasoning. Right now
the only one is being more compatible with IA2.

See also:
https://mail.gnome.org/archives/gnome-accessibility-devel/2013-August/msg00013.html
atktext: Fixing some typos on atk_text_get_text_at_offset deprecation

Also updated atk_text_get_text_[before/after]_offset deprecation
and documentation.
Release 2.9.4