build: Force linking against the locally compiled ndn-cxx library

When ndn-cxx is configured to be linked against static libraries (e.g.,
a static version of boost libraries) while ndn-cxx library is being
compiled as a shared library, waf adds '-L<static/path>' before '-L.'.
This can result in compilation failure when the system has a different
version of the ndn-cxx library installed.

This commit also makes a minor improvement for cryptopp library
detection.

Change-Id: Ia42a21b51a51a867a1b455a95d1cf5de6b21881f
diff --git a/.waf-tools/cryptopp.py b/.waf-tools/cryptopp.py
index 8244d53..93abd84 100644
--- a/.waf-tools/cryptopp.py
+++ b/.waf-tools/cryptopp.py
@@ -101,7 +101,7 @@
         self.fatal('CryptoPP not found or is not usable')
 
     isLibWorking = False
-    for defines in ['', 'CRYPTOPP_DISABLE_ASM']:
+    for defines in [[], ['CRYPTOPP_DISABLE_ASM']]:
         try:
             self.check_cxx(msg='Checking if CryptoPP library works',
                            fragment=CRYPTOPP_CHECK_FRAGMENT,