Clean comments, namespace, and variable names

This CL removes TODOs and email addresses from comments, unifies some
namespaces and cleans a few variable names.  It is a copy of multiple
CLs on the widevine side.

Change-Id: I1bb649096476a5001a56d746427399de6a88ff69

libwvdrmengine/cdm/core/src/string_conversions.cpp

@@ -75,10 +75,10 @@ std::string b2a_hex(const std::string& byte) {
                    byte.length());
 }
 
-// Filename-friendly base64 encoding (RFC4648), commonly referred as
-// Base64WebSafeEncode.
-// This is the encoding required by GooglePlay to interface with the
-// provisioning server's Apiary interface as well as for certain license server
+// Filename-friendly base64 encoding (RFC4648), commonly referred to
+// as Base64WebSafeEncode.
+// This is the encoding required to interface with the provisioning
+// server's Apiary interface as well as for certain license server
 // transactions.  It is also used for logging certain strings.
 // The difference between web safe encoding vs regular encoding is that
 // the web safe version replaces '+' with '-' and '/' with '_'.