The numeric value of NM_SETTING_PROXY_METHOD_NONE should be zero,
as that is the more natural default.
Also, cast all uses of the enum values in g_object_set() to
(int).
libnm-core: pac-script property in NMSettingProxy now represents the
script itself not the location. It ensures that the connection is
self contained.
nmcli: Supports loading of PAC Script via file path or written explicitly.
Unnecessary APIs have been removed from nm-setting-proxy, client like
nm-connection-editor are expected to create a PAC script snippet the load
the location of file in NM.
libnm-core has been expanded to include proxy settings which clients
like nmcli, nm-connection-editor use to configure proxy in PacRunner. It
offers three modes i.e 'auto', 'manual'and 'none' and accordingly take
data to configure PacRunner. The modes matches on the PacRunner side too.
