[ADD] view.rng: new @options attribute for field widgets

This attribute is supposed to be a JSON dict containing
arbitrary widget-specific options. To be ignored if the
widget or client does not support them.

bzr revid: odo@openerp.com-20111221110301-ejjm4s4f2vttw2r6

openerp/addons/base/rng/view.rng

@@ -537,6 +537,10 @@
             <rng:optional><rng:attribute name="filters"/></rng:optional>
             <rng:optional><rng:attribute name="statusbar_visible"/></rng:optional>
             <rng:optional><rng:attribute name="statusbar_colors"/></rng:optional>
+            <!-- Widget *static* options defined as an arbitrary JSON dict, with
+                 widget-dependent parameters. To be ignored if widget/client does
+                 not support them. -->
+            <rng:optional><rng:attribute name="options"/></rng:optional>
             <rng:zeroOrMore>
                 <rng:choice>
                     <rng:ref name="diagram"/>