#18 Allow an xml-like notation for the objects

[ponchy]

I was requested to offer the possibility to write objects using xml-like notation because some people use to find it easier to read.

By theway, the 2 objects notations should be mixable at will.

[ponchy]

a 1st implementation is done.

Notes :

• namespaces and xml comments are forbidden (there is only a pseudo namespace 'scn' for the keywords
• the 'as' operator becomes scn:as='XXX'
• the collections are tackled this way :

    <scn:collection>value</scn:collection>

• maps are tackled this way :

    <scn:map><scn:key>aa</scn:key<scn:value>val</scn:value></scn:map>

• These fragments are valid

    <list>[ 1 , 2, 3 ]</list>

    <scn:map>
       "micket"=>"minnie"
       "brad"=>"angie" 
    </scn:map>

[ponchy]

This tickets needs to be tested before closing.