Wonderland: changed temporary field access

[Felix Mayerhuber]

Hi,

for everyone working with the model transformation solution in the
master branch: From now on temporary fields are accessed with the prefix
"#" instead of the prefix "temp.". This was done, because otherwise the
support of nested field access has a bug (if a field which shall be
accessed in a nested way is called temp). So "temp.test" need to be
written from now on "#test" instead.

Kind regards
Felix