Integrate priority-based buffer into `Client` and `Server`

[LouYu2015]

Summary:

• Added PacketBuffer.cs
• Integrated priority-based packet buffer into Client and Server
• Added unit test project

---

Communications in Communications/PacketBuffer.cs:

• New abstract class PacketBuffer
• New class QueueBuffer
• New class PriorityBuffer
• New class BandwidthControlBuffer
• New class GenericController

---

Communications.Packet in Communication/Packet.cs:

• New method GetLength

---

Communications.Client in Communications/Client.cs:

• New public-get private-set field DefaultPriority
• Field type change: SendQueue from Queue<Packet> to PacketBuffer
• Field type change: ReceiveQueue from Queue<Packet> to QueueBuffer
• Parameter list change: Start has new optional parameter UsePriorityQueue
• Parameter list change: Send has new optional parameter Priority
• Return value change: Send will return false if the packet is not added to queue
• Behavior change: SendPackets won't clone packet because packet is already cloned before adding to buffer.

---

Communications.Server in Communications/Server.cs:

• New public-get private-set field PriorityQueueEnabled
• New public-get private-set field DefaultPriority
• Field type change: SendQueues from Dictionary<string, Queue<Packet>> to Dictionary<string, PacketBuffer>
• Field type change: ReceiveQueue from Queue<Packet> to QueueBuffer
• Parameter list change: Start has new optional parameter UsePriorityQueue
• Parameter list change: Send has new optional parameter Priority
• New private method: CreateBufferIfClientIsNew

---

Communications in Communications/Constants.cs:

• New type PacketPriority

[CaiB]

Also, removing all of the testing-related DLL/XML files would probably be best, since we probably can't actually host them with the license on this repository.

If we do remove those files, what does someone need to do after cloning the repository to make everything work again?

[LouYu2015]

I found that VS can automatically restore packages folder if I delete UnitTest\bin. Maybe the reason why it failed previously is that VS won't rebuild packages folder if UnitTest\bin exists. Now we can safely remove the files in it. However, I may need to copy codes to another branch so that those files won't show up in the history (they will remain in this branch's history even if I delete them).

[LouYu2015]

I successfully removed the history of packages folder by using filter-branch. Now we can keep this branch.

[LouYu2015]

Revision is pushed to the branch: https://github.com/huskyroboticsteam/Scarlet/pull/1/commits/9503196e409e439ed8c9d4d80e31fb9289b00551

[CaiB]

I also just went through and made a lot of style-related changes (no functional changes should have been made). The big two things that I saw were omitting this.. We like to use this. for all field accessors/assignments to make it clear that it's a field, and hopefully reduce the number of times we accidentally type the wrong variable. The other thing was just various spacing changes. Bringing blocks into single lines, and reducing the amount of wasted space in comments. With these changes, I reduced the linecount by almost 100 lines, while (in my opinion) making things more readable.

Have a look at the kinds of changes that I made, so that you can keep them in mind for future changes.

@Baldstrom We should probably better define our style guidelines for things like this, to help others understand what we expect. Right now, our documentation is a bit lacking in that department, and we will need to make it more clear if we have more people contributing.

[LouYu2015]

Unit test passed after merging. However, there is a minor issue: there are two entries of .vs in .gitignore now.