OEMCrypto v15.1 Updates

This CL updates documentation, reference code, and unit tests to match
the OEMCrypto v15.1 API.

1. The design for the Full Decrypt Path Testing application has
changed. Instead of reading hashes from an external file, it will use
a single key frame and modify it to match the desired size.  The test
application will then compute the hash and encrypt the frame.  For
OEMCrypto, this means that there will not be a call to
OEMCrypto_InitializeDecryptHash before the frame and
OEMCrypto_SetDecryptHash after the frame. Instead, there will be a
single call to OEMCrypto_SetDecryptHash before the frame. The function
OEMCrypto_InitializeDecryptHash will not be used.

2. The "Shared License" feature is not used by any production
server. This functionality is no longer required and OEMCrypto may
reject licenses with a nonzero bit 23 in the key control block.

util/include/log.h

@@ -7,6 +7,8 @@
 #ifndef WVCDM_UTIL_LOG_H_
 #define WVCDM_UTIL_LOG_H_
 
+#include "util_common.h"
+
 namespace wvcdm {
 
 // Simple logging class. The implementation is platform dependent.
@@ -25,10 +27,11 @@ extern LogPriority g_cutoff;
 // This function is supplied for cases where the system layer does not
 // initialize logging.  This is also needed to initialize logging in
 // unit tests.
-void InitLogging();
+CORE_UTIL_EXPORT void InitLogging();
 
-void Log(const char* file, const char* function, int line, LogPriority level,
-         const char* fmt, ...);
+CORE_UTIL_EXPORT void Log(
+    const char* file, const char* function, int line, LogPriority level,
+    const char* fmt, ...);
 
 // Log APIs
 #ifndef LOGE