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/deviceSpecParser.cpp

@@ -10,6 +10,9 @@
 #include "deviceSpecp.hh"
 #include "deviceSpecl.hh"
 
+namespace hk {
+namespace device {
+
 std::string DeviceManager::readDeviceFile(const std::string& filename)
 {
     std::ifstream file(filename);
@@ -61,3 +64,6 @@ void DeviceManager::parseAllDeviceSpecs(void)
             "Check specs for errors");
     }
 }
+
+} // namespace device
+} // namespace hk