pfSense

In first commit, I expose the NBDD servers in GUI, replace some spaces by tabs and fix the GUI bugs
Commit 1: OpenVPN: expose NBDD servers option and fix gui bugs
- add option to push NBDD servers to client in both server and specific client overrides
- in OpenVPN server, when enabling NetBios options, then WINS Servers, disabling Netbios options now properly hides WINS Servers fields
- properly do not save NetBios settings in config when NetBios option is disabled in both server and client specific overrides
- in client specific overrides: NTP and DNS options: use javascript instead of toggles class because the latter causes inverted results when repeating clicks too quickly. This also matches the code used in the server page

Optional second commit:
OpenVPN: Rename deprecated settings variables
- the netbios old settings variables are automatically converted when loading the settings file, so deprecate them in openvpn.inc

Optional last commit
Fix upstream empty() / 0 confusion
- if you set DNS/NTP servers values to 0, they will be saved in config, but on edit, the field is hidden, yet the server is properly saved as '0'.
This is because testing string 0 is false and empty() can be false for 'boolean true' and true for numeric '0'
This patch properly tests if a field has entries, text or numeric, excluding NULL, unset, empty and booleans