sip: codestyle changes

Shuffle the code around and make use of docstrings to conform to
the newly introduced coding style as described in `HACKING.md`

This commit also introduces docstrings describing each source file.

plugins/sip/calls-sip-provider.c

@@ -24,23 +24,35 @@
 
 #define G_LOG_DOMAIN "CallsSipProvider"
 
-#define SU_ROOT_MAGIC_T CallsSipProvider
-
-#include "calls-sip-provider.h"
+#define SIP_ACCOUNT_FILE "sip-account.cfg"
 
 #include "calls-message-source.h"
 #include "calls-provider.h"
-#include "calls-sip-origin.h"
-#include "calls-sip-util.h"
 #include "calls-sip-enums.h"
+#include "calls-sip-origin.h"
+#include "calls-sip-provider.h"
+#include "calls-sip-util.h"
 #include "config.h"
 
 #include <libpeas/peas.h>
 #include <sofia-sip/nua.h>
 #include <sofia-sip/su_glib.h>
 
+/**
+ * SECTION:sip-provider
+ * @short_description: A #CallsProvider for the SIP protocol
+ * @Title: CallsSipProvider
+ *
+ * #CallsSipProvider is derived from #CallsProvider and is responsible
+ * for setting up the sofia-sip stack.
+ */
 
-#define SIP_ACCOUNT_FILE "sip-account.cfg"
+enum {
+  PROP_0,
+  PROP_SIP_STATE,
+  PROP_LAST_PROP,
+};
+static GParamSpec *props[PROP_LAST_PROP];
 
 struct _CallsSipProvider
 {
@@ -54,13 +66,6 @@ struct _CallsSipProvider
   gchar *filename;
 };
 
-enum {
-  PROP_0,
-  PROP_SIP_STATE,
-  PROP_LAST_PROP,
-};
-static GParamSpec *props[PROP_LAST_PROP];
-
 static void calls_sip_provider_message_source_interface_init (CallsMessageSourceInterface *iface);
 
 
@@ -339,6 +344,12 @@ calls_sip_provider_dispose (GObject *object)
 }
 
 
+static void
+calls_sip_provider_class_finalize (CallsSipProviderClass *klass)
+{
+}
+
+
 static void
 calls_sip_provider_class_init (CallsSipProviderClass *klass)
 {
@@ -430,12 +441,6 @@ calls_sip_provider_new ()
 }
 
 
-static void
-calls_sip_provider_class_finalize (CallsSipProviderClass *klass)
-{
-}
-
-
 G_MODULE_EXPORT void
 peas_register_types (PeasObjectModule *module)
 {