[ODE] XODE - finalisation

[Royce Mitchell III]

I finally had a chance to look it over, and I have found some 
inconsistencies, I think...

Why this:

     <cylinder
       radius="1"
       length="2">
     </cylinder>

and not:

     <cylinder
       radius="1"
       length="2"/>

Why this:

<imatrix
       d_1_1="0" d_1_2="1" d_1_3="2"
       d_2_1="1" d_2_2="0" d_2_3="1"
       d_3_1="0" d_3_2="1" d_3_3="0">
     </imatrix>

and not:

<imatrix
       d_1_1="0" d_1_2="1" d_1_3="2"
       d_2_1="1" d_2_2="0" d_2_3="1"
       d_3_1="0" d_3_2="1" d_3_3="0" />

same thing for tmatrix ( which is used both ways )...

You have this early in the document:

<cylinder
            radius="2"
            length="6">
        </cylinder>

but this later in the example data:

<cylinder>
     <radius>1</radius>
 </cylinder>

you have this early in the document:

<mass total="1">
     <centerGravity x="1" y="1" z="1" />
     <imatrix
       d_1_1="0" d_1_2="1" d_1_3="2"
       d_2_1="1" d_2_2="0" d_2_3="1"
       d_3_1="0" d_3_2="1" d_3_3="0">
     </imatrix>
</mass>

but something like this occurs several times in the example data:

<mass>5</mass>