Standardize lp_get_parent_directory function

[DavidWells]

We need to make this a generic function that lives in /shared/ so all templates can use the same function to grab this path.

This is for standardizing templating across all post types

Something like: inbound_get_parent_directory will work

[atwellpub]

This is available now. Also went ahead and converted landing pages templates to use the shared function. Legacy still exists.

[atwellpub]

Looks like b/c landing page's config files are loaded before init and plugins_loaded the config.php cannot use methods defined in shared. Shared is loaded in plugins_loaded hook. I reversed my commit the changed lp_get_parent_directory to inbound_get_parent_directory.

[DavidWells]

We are going to need some functionality loaded from /shared/ before the plugins_loaded hook.

Look like we might need to have a loader for stuff that needs to register quicker?

like:

trigger on init
private static function load_init_shared_files() {

}
trigger on plugins_loaded
private static function load_shared_files() {

}

[atwellpub]

Loading the template config data in init (init happens after plugins_loaded) has allowed us to convert lp_get_parent_directory to inbound_get_parent_directory().