wrap all library code into namespace if VCMI_LIB_NAMESPACE is defined

preparation for having client and server in a single process

lib/filesystem/CCompressedStream.cpp

@@ -12,6 +12,8 @@
 
 #include <zlib.h>
 
+VCMI_LIB_NAMESPACE_BEGIN
+
 static const int inflateBlockSize = 10000;
 
 CBufferedStream::CBufferedStream():
@@ -189,3 +191,5 @@ bool CCompressedStream::getNextBlock()
 	reset();
 	return true;
 }
+
+VCMI_LIB_NAMESPACE_END