Revert "Move C++ helpers into |bssl| namespace."

This reverts commit 09feb0f3d95a2bc58ce0faaf14256d3bd30f52a4.

(In order to make WebRTC happy this also needs to be reverted.)

tool/tool.cc

diff --git a/tool/tool.cc b/tool/tool.cc
index 8519108..34851b4 100644
--- a/tool/tool.cc
+++ b/tool/tool.cc
@@ -29,8 +29,6 @@
 #include "internal.h"
 
 
-namespace bssl {
-
 typedef bool (*tool_func_t)(const std::vector<std::string> &args);
 
 struct Tool {
@@ -81,8 +79,7 @@
   }
 }
 
-
-static int Main(int argc, char **argv) {
+int main(int argc, char **argv) {
 #if defined(OPENSSL_WINDOWS)
   // Read and write in binary mode. This makes bssl on Windows consistent with
   // bssl on other platforms, and also makes it consistent with MSYS's commands
@@ -127,9 +124,3 @@
 
   return !tool(args);
 }
-
-}  // namespace bssl
-
-int main(int argc, char **argv) {
-  return bssl::Main(argc, argv);
-}