Use consistent name casing (#1268)

- Use PascalCase for classes, with uppercase acronyms.
- Use camelCase for function and variables. First word/acronym is always
  lowercase, otherwise acronyms are uppercase.

Also, make the packet classes' `tag` properties `static`.

src/encoding/base64.js

@@ -30,8 +30,8 @@ if (Buffer) {
     return new Uint8Array(b.buffer, b.byteOffset, b.byteLength);
   };
 } else {
-  encodeChunk = buf => btoa(util.uint8ArrayToStr(buf));
-  decodeChunk = str => util.strToUint8Array(atob(str));
+  encodeChunk = buf => btoa(util.uint8ArrayToString(buf));
+  decodeChunk = str => util.stringToUint8Array(atob(str));
 }
 
 /**