libobs: Make obs_source_save and obs_source_load internal

There shouldn't be any need to call these functions manually.  These
functions are called automatically by obs_save_sources and
obs_load_sources.

libobs/obs-internal.h

@@ -566,6 +566,9 @@ extern bool obs_source_init_context(struct obs_source *source,
 extern bool obs_source_init(struct obs_source *source,
 		const struct obs_source_info *info);
 
+extern void obs_source_save(obs_source_t *source);
+extern void obs_source_load(obs_source_t *source);
+
 extern void obs_source_destroy(struct obs_source *source);
 
 enum view_type {

libobs/obs.h

@@ -791,22 +791,6 @@ EXPORT bool obs_source_active(const obs_source_t *source);
  */
 EXPORT bool obs_source_showing(const obs_source_t *source);
 
-/**
- * Sometimes sources need to be told when to save their settings so they
- * don't have to constantly update and keep track of their settings.  This will
- * call the source's 'save' callback if any, which will save its current
- * data to its settings.
- */
-EXPORT void obs_source_save(obs_source_t *source);
-
-/**
- * Sometimes sources need to be told when they are loading their settings
- * from prior saved data.  This is different from a source 'update' in that
- * it's meant to be used after the source has been created and loaded from
- * somewhere (such as a saved file).
- */
-EXPORT void obs_source_load(obs_source_t *source);
-
 /** Specifies that async video frames should be played as soon as possible */
 #define OBS_SOURCE_FLAG_UNBUFFERED             (1<<0)
 /** Specifies to force audio to mono */