Update BrainFuck.cs

Cleaned up code and added comments. Using regions at the moment since I am just copying
and pasting this into the GitHub editor. I'll create the files as they are organized
on my machine soon. I'll also keep a condensed file for easier implementation so only
one file needs to be added to a project to implement the interpreter.

New implementation methods added:

Static implementation examples:

    Process file:
        BrainFuck.Run("path/to/code.bs");

    Process string:
        BrainFuck.Run("++++++++++[>+++++++>++++++++++>+++>+<<<<-]>++.>+.+++++++..+++.>++.<<+++++++++++++++.>.+++.------.--------.>+.>.");

Read buffer on instantiation:
    byte[] buffer = Encoding.GetEncoding(1252).GetBytes("++++++++++[>+++++++>++++++++++>+++>+<<<<-]>++.>+.+++++++..+++.>++.<<+++++++++++++++.>.+++.------.--------.>+.>.");
    BrainFuck bf = new BrainFuck(buffer);
    bf.Run();
Read file on instantiation:
    BrainFuck bf = new BrainFuck("path/to/code.bs");
    bf.Run();

Read string on instantiation:
    BrainFuck bf = new BrainFuck("++++++++++[>+++++++>++++++++++>+++>+<<<<-]>++.>+.+++++++..+++.>++.<<+++++++++++++++.>.+++.------.--------.>+.>.");
    bf.Run();