Update the menus for multisite, see #1
Add is_wordpoints_network_active() function and unit tests
Add functions for options which are site-wide only when network-active

These options are just regular options, even in multisite, except when
the plugin is network activated. Then they are site options. Also adds
related unit tests. See #1.
Fix a copy-pasta in the docs for wordpoints_update_network_option()
Add wordpoints_delete_network_option() and related unit tests
Make the excluded users option a site-option when network activated

The rest of the time, it will just be a regular option. See #1
Make the default points type option a site option when network-active

Remains a regular option otherwise. See #1
Include /wp-admin/includes/plugin.php in is_wordpoints_network_active()

To ensure that `is_plugin_active_for_network()` will be defined. See #1.
Merge branch 'multisite'