Make comments in main an init doxygen compatible

Fix typos where appropriate
Update license/copyright

src/init.cpp

@@ -1,6 +1,6 @@
 // Copyright (c) 2009-2010 Satoshi Nakamoto
 // Copyright (c) 2009-2014 The Bitcoin developers
-// Distributed under the MIT/X11 software license, see the accompanying
+// Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #if defined(HAVE_CONFIG_H)
@@ -60,7 +60,7 @@ bool fFeeEstimatesInitialized = false;
 #define MIN_CORE_FILEDESCRIPTORS 150
 #endif
 
-// Used to pass flags to the Bind() function
+/** Used to pass flags to the Bind() function */
 enum BindFlags {
     BF_NONE         = 0,
     BF_EXPLICIT     = (1U << 0),
@@ -175,9 +175,9 @@ void Shutdown()
     LogPrintf("%s: done\n", __func__);
 }
 
-//
-// Signal handlers are very limited in what they are allowed to do, so:
-//
+/**
+ * Signal handlers are very limited in what they are allowed to do, so:
+ */
 void HandleSIGTERM(int)
 {
     fRequestShutdown = true;