feat(caps): add cache clearing to /caps

Add /caps clear to wipe the local capabilities cache.
Implement autocomplete for new subcommand.

src/xmpp/capabilities.c

@@ -23,6 +23,7 @@
 #include "plugins/plugins.h"
 #include "config/files.h"
 #include "config/preferences.h"
+#include "xmpp/connection.h"
 #include "xmpp/xmpp.h"
 #include "xmpp/stanza.h"
 #include "xmpp/form.h"
@@ -271,6 +272,16 @@ caps_map_jid_to_ver(const char* const jid, const char* const ver)
     g_hash_table_insert(jid_to_ver, strdup(jid), strdup(ver));
 }
 
+void
+caps_cache_clear(void)
+{
+    g_hash_table_remove_all(jid_to_ver);
+    g_hash_table_remove_all(jid_to_caps);
+    cache = g_key_file_new();
+    caps_prof_keyfile.keyfile = cache;
+    save_keyfile(&caps_prof_keyfile);
+}
+
 gboolean
 caps_cache_contains(const char* const ver)
 {

src/xmpp/capabilities.h

@@ -28,5 +28,6 @@ void caps_map_jid_to_ver(const char* const jid, const char* const ver);
 gboolean caps_cache_contains(const char* const ver);
 GList* caps_get_features(void);
 char* caps_get_my_sha1(xmpp_ctx_t* const ctx);
+void caps_cache_clear(void);
 
 #endif