perf: kcp2k V1.6 - unreliable channel & improvements

fix: fixed Chat example scene for 2018.4

fix: kcp2k updated to V1.5. bigger send/recv window size defaults bec…

…ause Mirror sends a lot of data. fixes a bug where some projects would encounter ever growing latencies because kcp didn't process/send data fast enough, causing slowly growing send/recv buffers. also shows MaxSend/RecvRate in debug gui now.

fix: NetworkWriterTest.cs failing due to Blittable removal (MirrorNet…

…working#2530)

This commit compliments dd4d344, and makes all tests in NetworkWriterTest.cs pass with flying colours. Gold star!

fix: adding newline before StackTrace

this avoids the first line of the stacktrace being on the same line as the Exception. this is better because the Exception line could be line and it is easy to miss the first stack trace line.

feat: Adding default folder as argument for ScriptableObjectUtility (M…

…irrorNetworking#2513)

This allows ScriptableObjectUtility to be used for other folders not just Asset/Mirror

fix: DisallowMultipleComponent on all transports (MirrorNetworking#2507)

Co-authored-by: MrGadget1024 <[email protected]>

fix: prevent allocation of massive array (MirrorNetworking#2465)

* fix: prevent allocation of massive array

A poison message could contain an invalid length causing us to allocate massive arrays

* throw exception instead

* Update Assets/Mirror/Runtime/NetworkReader.cs

Co-authored-by: James Frowen <[email protected]>

* test for ReadArray

* swapping order of equation so that length doesnt overflow

* adding test case

* adding more tests for array length

* swapping order

* fixing expected message

Co-authored-by: James Frowen <[email protected]>

fix: Updated Basic example to work in Unity 2018.4

feat(SimpleWebTransport): adding option to allow for tls outside of t…

…he transport