small changes to allow preset management

The goal is not to send preset data back to the requester in order to avoid
reloading the preset on itself whenever it is requested.

The solution is to use a special sender ID 'g' that gets transformed to 'p'
by [netpd-r]. Presets are requested on 'g' and sent to 'p'.
add closeall method: /unpatch/netcloseall
make smaller to make room for preset buttons
preset load (GUI and functionality)
preset save (GUI and functionality)
add load and save buttons to GUI
check 'hide argument and object name' for GOP
improve button behavior (block during load)
Merge branch 'master' into presetsave
bump version to 2.1.2