TODO doc for Glade namespace.

There are in total 21 xml to document in Glade. Right now there are 19 xml not documented in any proportion.
The idea is to have a easy way to know what documentation is missing, if you want to help or are helping please take out the xml that you commit
from the missing list. For documentation that take some time to finish (like HTML, TextBuffer, etc) the best is that you but your name and email
next to the file in this list to acknowledge that you are working in it (is recommendable that you suscribe to the mono-docs  mailing list).

Following is the list of undocumented xml:

AccelInfo.xml
ApplyCustomPropFunc.xml
AtkActionInfo.xml
AtkRelationInfo.xml
BuildChildrenFunc.xml
ChildInfo.xml
FindInternalChildFunc.xml
Global.xml
HandlerNotFoundException.xml
Interface.xml
NewFunc.xml
Parser.xml
Property.xml
RawXMLConnectFunc.xml
SignalInfo.xml
Standard.xml
WidgetInfo.xml
XMLConnectFunc.xml
XMLCustomWidgetHandler.xml
