modified some tests of testsuite

["Ralf Berger" <ralf@itedo.com>]

hi All,

we have uploaded two more modified test files:

appstructure-screentip.htm
    test2: typo: getAppStructureByName vs. getAppStructuresByName

node-pict.htm
    no support for constant PICTURE_NODE
    nodeValue should be compared with ""
    ownerPicture of 'root' points to itself
    the picture id is an attribute
    strings should be compared with ""

Note: possibly more changes coming in node-pict.htm

Cheers,
- Ralf