docs: Improve netaddress comments

- Improve IsRFC methods docs
- Improve {Is,Set}Internal docs
- Add tor methods docs
- Add IsIPv{4,6} docs
- Add IsValid docs
- Add IsRoutable docs
- Improve GetGroup docs
- Add CService::GetSockAddr docs
- Add CService::GetKey docs
- Add CSubNet::Match docs
- Add NetmaskBits docs
- Add CNetAddr default constructor docs

src/netaddress.h

@@ -48,10 +48,6 @@ class CNetAddr
         void SetRaw(Network network, const uint8_t *data);
 
     public:
-        /**
-          * Transform an arbitrary string into a non-routable ipv6 address.
-          * Useful for mapping resolved addresses back to their source.
-         */
         bool SetInternal(const std::string& name);
 
         bool SetSpecial(const std::string &strName); // for Tor addresses
@@ -69,8 +65,8 @@ class CNetAddr
         bool IsRFC4380() const; // IPv6 Teredo tunnelling (2001::/32)
         bool IsRFC4843() const; // IPv6 ORCHID (2001:10::/28)
         bool IsRFC4862() const; // IPv6 autoconfig (FE80::/64)
-        bool IsRFC6052() const; // IPv6 well-known prefix (64:FF9B::/96)
-        bool IsRFC6145() const; // IPv6 IPv4-translated address (::FFFF:0:0:0/96)
+        bool IsRFC6052() const; // IPv6 well-known prefix for IPv4-embedded address (64:FF9B::/96)
+        bool IsRFC6145() const; // IPv6 IPv4-translated address (::FFFF:0:0:0/96) (actually defined in RFC2765)
         bool IsTor() const;
         bool IsLocal() const;
         bool IsRoutable() const;