build: Fixing and suppressing all warnings

clang generates a number of harmless warnings originated from cryptopp
library.

Change-Id: I676e7b6d60588867f55a2ce1cd88ef263c3e38df
diff --git a/src/security/key-chain.cpp b/src/security/key-chain.cpp
index ee56f8c..e61013f 100644
--- a/src/security/key-chain.cpp
+++ b/src/security/key-chain.cpp
@@ -35,7 +35,7 @@
   , privateKeyStorage_(privateKeyStorage)
   , policyManager_(policyManager)
   , encryptionManager_(encryptionManager)
-  , maxSteps_(100)
+  // , maxSteps_(100)
 {
   if (publicInfoStorage_ == DefaultIdentityStorage)
     {