Added option to only import subset of tree parameters

[linakrisztian]

Option to give only subset of tree parameters. If option not given all parameters will be computed (as before).

Changed:

• added optional parameter treeparamset
• set input (buildings, ndom, ndvi) to optional if subset of tree parameters given (and the data are not required for them)
• removed region setting: only vector operations
• fixed typos and cleanup

[metzm]

Looks good to me!