added utility to hide console echo for entering passwords

include/fc/io/console.hpp

@@ -0,0 +1,8 @@
+#pragma once
+namespace fc 
+{
+   /** enables / disables echoing of console input, useful for 
+    *  entering passwords on the console.
+    */
+   void set_console_echo( bool enable_echo );
+} // namespace fc

src/io/console.cpp

@@ -0,0 +1,46 @@
+#include <iostream>
+#include <string>
+
+namespace fc {
+
+#ifdef WIN32
+#include <windows.h>
+
+void set_console_echo( bool enable_echo )
+{
+   auto stdin_handle = GetStdHandle( STD_INPUT_HANDLE );
+   DWORD mode = 0;
+   GetConsoleMode( stdin_handle, &mode );
+   if( enable_echo )
+   {
+      SetConsoleMode( stdin_handle, mode | ENABLE_ECHO_INPUT );
+   }
+   else
+   {
+      SetConsoleMode( stdin_handle, mode & (~ENABLE_ECHO_INPUT) );
+   }
+}
+
+#else // NOT WIN32
+#include <termios.h>
+#include <unistd.h>
+
+void set_console_echo( bool enable_echo )
+{
+   termios oldt;
+   tcgetattr(STDIN_FILENO, &oldt);
+   termios newt = oldt;
+   if( enable_echo )
+   {
+      newt.c_lflag |= ~ECHO;
+   }
+   else
+   {
+      newt.c_lflag &= ~ECHO;
+   }
+   tcsetattr(STDIN_FILENO, TCSANOW, &newt);
+}
+
+#endif // WIN32
+
+} // namespace fc