perf: messages should be value types (MirrorNetworking#987)

feat: safer and consistent writers names (MirrorNetworking#979)

* WriteUInt16

* WriteUInt16 weaver

* WriteUInt32

* WriteUInt64

* WriteByte

* WriteSbyte

* WriteChar

* WriteBoolean

* WriteInt16

* WriteInt32

* WriteInt64

* WriteDouble

* WriteDecimal

* WriteString

* WriteBytes

* WriteVector2

* WriteVector3

* WriteVector4

* WriteVector2Int

* WriteVector3Int

* WriteColor

* WriteColor32

* WriteQuaternion

* WritePlane

* WriteRay

* WriteMatrix4x4

* WriteGuid

* WriteNetworkIdentity

* WriteTransform

* WriteGameObject

* Keep consistent line breaks

* add new define so asset maintainers can tell if the new methods are available

fix: Telepathy updated to latest version. connectionId counter is pro…

…perly reset after stopping server.

fix: Don't increment counter in Awake (MirrorNetworking#971)

Doing it in Awake and also before assigning to clients skips connection ID 1.

fix: do not accumulate changes if there are no observers fixes Mirror…

…Networking#963 (MirrorNetworking#964)

* fix: do not accumulate changes if there are no observers MirrorNetworking#963

* Update NetworkIdentity.cs

fix: maintain Unity's copyright notice (MirrorNetworking#961)

fix: Telepathy forgot to set socket options for accepted clients on t…

…he server

perf: Recycle argument writer to avoid allocations (MirrorNetworking#945

)

* Recycle argument writer

* Get a pooled networkwriter for argumens

* Use pool,  not static variable

* Use explicit type

* Remove blank space

* Recycle writer in the weaver where it is allocated

perf: remove allocations during syncvar sync (MirrorNetworking#946)

fix: properly stop client and server in OnApplicationQuit so that cli…

…ents still get a chance to send then 'quit' packet instead of just timing out. Also fixes a bug where OnStopServer/OnStopClient were not called when stopping the Editor. (MirrorNetworking#936)