Eliminate the C FFI; Namespace lib API and DeviceManager

We decided to get rid of the C FFI for libs. It was becoming too intricate
and complicated. It was becoming a technical burden and expanding into
too much extra code. It's unfortunate, but we'll have to give up on getting
out-of-tree hot-loadable libraries the easy way.

It's possible to still do it with cross compilation or by keeping track
of the libstdc++ version that the running harikoff binary was compiled
against. Then we can ensure that our loadable lib code is linked against
that same libstdc++ code and this should ensure ABI stability.

hcore/deviceManager/deviceManager.cpp

@@ -8,6 +8,9 @@
 #include <opts.h>
 #include <deviceManager/deviceManager.h>
 
+namespace hk {
+namespace device {
+
 std::vector<std::shared_ptr<InteroceptorDeviceSpec>>
     DeviceManager::interoceptorDeviceSpecs;
 std::vector<std::shared_ptr<ExtrospectorDeviceSpec>>
@@ -20,12 +23,15 @@ const std::string DeviceManager::stringifyDeviceSpecs(void)
     std::ostringstream oss;
 
     for (const auto& spec : DeviceManager::interoceptorDeviceSpecs) {
-        oss << "Interoceptor " << CSenseDeviceSpec(*spec);
+        oss << "Interoceptor " << spec->stringify();
     }
 
     for (const auto& spec : DeviceManager::extrospectorDeviceSpecs) {
-        oss << "Extrospector " << CSenseDeviceSpec(*spec);
+        oss << "Extrospector " << spec->stringify();
     }
 
     return oss.str();
 }
+
+} // namespace device
+} // namespace hk