PATCH: AbiWord Sugar mode

Hi all,

This is a patch for the Sugar branch that starts abiword in a GtkPlug
so it can be plugged into the Sugar shell, and then simplifies the
interface significantly. Also attached is a necessary new file, which
goes in src/wp/ap/xp.

I'd appreciate feedback about whether I'm doing things in the right
places, and also on whether I'm creating the diff properly.

(it's a shockingly small amount of code, I know... but there was a lot
to learn before I could even figure out which code to touch, let alone
what to write.)

Erik

Changes
======
* Changed XAP_UnixFrameImpl::_createTopLevelWindow to create a gtkplug
instead of a gtkwindow
* Also in XAP_UnixFrameImpl::_createTopLevelWindow, disable the code
that "synthesized" a menu. This might be the wrong place to turn the
menu off, but it works.
* Disable XAP_UnixFrameImpl::_rebuildMenus, because it was segfaulting too.
* Edited xap_Features.h to include embedded features when building for sugar.
* Set the default toolbar layouts to the Olpc bar in ap_Prefs_SchemeIds.h.
* Disable the several Defun1's (viewStd, viewFormat, viewTable,
viewExtra) in ap_EditMethods.cpp.
* Change ap_Toolbar_Layouts_All.h to point to the Olpc toolbar.
* Create ap_TB_Layouts_OlpcOps.h