*: add "noexcept" to many, many function prototypes

This eliminates some overhead, because the compiler doesn't need to
consider these functions throwing.

src/neighbor/Glue.cxx

@@ -93,7 +93,7 @@ NeighborGlue::Close()
 }
 
 NeighborGlue::List
-NeighborGlue::GetList() const
+NeighborGlue::GetList() const noexcept
 {
 	List result;
 

src/neighbor/Glue.hxx

@@ -71,7 +71,7 @@ public:
 	 * plugins.
 	 */
 	gcc_pure
-	List GetList() const;
+	List GetList() const noexcept;
 };
 
 #endif

src/neighbor/Registry.cxx

@@ -36,7 +36,7 @@ const NeighborPlugin *const neighbor_plugins[] = {
 };
 
 const NeighborPlugin *
-GetNeighborPluginByName(const char *name)
+GetNeighborPluginByName(const char *name) noexcept
 {
 	for (auto i = neighbor_plugins; *i != nullptr; ++i)
 		if (strcmp((*i)->name, name) == 0)

src/neighbor/Registry.hxx

@@ -32,6 +32,6 @@ extern const NeighborPlugin *const neighbor_plugins[];
 
 gcc_pure
 const NeighborPlugin *
-GetNeighborPluginByName(const char *name);
+GetNeighborPluginByName(const char *name) noexcept;
 
 #endif

src/neighbor/plugins/SmbclientNeighborPlugin.cxx

@@ -169,7 +169,7 @@ ReadServers(NeighborExplorer::List &list, const char *uri)
 
 gcc_pure
 static NeighborExplorer::List
-DetectServers()
+DetectServers() noexcept
 {
 	NeighborExplorer::List list;
 	const std::lock_guard<Mutex> protect(smbclient_mutex);
@@ -181,7 +181,7 @@ gcc_pure
 static NeighborExplorer::List::const_iterator
 FindBeforeServerByURI(NeighborExplorer::List::const_iterator prev,
 		      NeighborExplorer::List::const_iterator end,
-		      const std::string &uri)
+		      const std::string &uri) noexcept
 {
 	for (auto i = std::next(prev); i != end; prev = i, i = std::next(prev))
 		if (i->uri == uri)