* src/xwidget.h (xwidget_view): Convert member `model' to Lisp_Object.
(XXWIDGET_VIEW_P, XXWIDGET_VIEW): Add standard macros to manipulate xwidget_view.
* src/xwidget.c: Fix access to model in xwidget_view (now a Lisp_Object).
* src/xwidget.c (Fmake_xwidget): Use XSETXWIDGET instead of XSETPSEUDOVECTOR.
* src/xwidget.h (XXWIDGET, XXWIDGET_VIEW): Use XUNTAG instead of XPNTR
(copied from XBUFFER and friends).
* src/xwidget.c: Fix access to w in xwidget_view (now a Lisp_Object)
* src/xwidget.h (xwidget_view): Convert member `w' to Lisp_Object.
* src/xwidget.c: Replace xwidget_views by Vxwidget_view_list.

xwidget_views was an hardcoded array of fixed lenght of `struct
xwidget_view', Vxwidget_view_list is a list of Lisp_Object.

* src/xwidget.h (xwidget_view): Remove member `initialized'.

This field was only used to determine whether a given xwidget_view was
initialized or not in `xwidget_views'. Now only initialized xwidget_view
are stored in Vxwidget_view_list.
Merge pull request #6 from daimrod/struct_to_Lisp_Object

Struct to lisp object