Make many more utility classes/headers public. (#76)

Moving these headers from src to include enables other libraries to use the
functionality provided.

* tcpsockets
* atomic_static
* raw_istream
* timestamp
* SafeThread
* Base64
* LEB128
* ConcurrentQueue

The classes have been moved into the wpi namespace as they're generic.

include/support/Base64.h

@@ -0,0 +1,23 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) FIRST 2015. All Rights Reserved.                             */
+/* Open Source Software - may be modified and shared by FRC teams. The code   */
+/* must be accompanied by the FIRST BSD license file in the root directory of */
+/* the project.                                                               */
+/*----------------------------------------------------------------------------*/
+
+#ifndef WPIUTIL_SUPPORT_BASE64_H_
+#define WPIUTIL_SUPPORT_BASE64_H_
+
+#include <cstddef>
+#include <string>
+
+#include "llvm/StringRef.h"
+
+namespace wpi {
+
+std::size_t Base64Decode(llvm::StringRef encoded, std::string* plain);
+void Base64Encode(llvm::StringRef plain, std::string* encoded);
+
+}  // namespace wpi
+
+#endif  // WPIUTIL_SUPPORT_BASE64_H_