Fixes issues when compiling with clang.

This version adds the possibility to pass an hg_init_info pointer to the engine constructor.

Fixes a problem with unpacking a response with 3 or more item (std::tie(a,b,c) = pack_response.as<X,Y,Z>())

With this version, thallium becomes a header-only library.

This version exposes the margo_top_finalize_callback family of functions. It also simplifies the finalization mechanism as well as replaces the internal function wrappers of the engine with calls to the margo macros.

• Corrected a compilation error when using clang

• Better serialization mechanism
• Type-checking possible using THALLIUM_DEBUG_RPC_TYPES

Added revive function for xstreams.

This version adds support for thallium::async_response::wait_any.

• Some small fixes to pre- and post-finalize callback hooks so that thallium works with Margo profiling.
• Minor correction to one of the examples.

• Corrected a problem with the order of pre-finalize callbacks
• Corrected static_cast in pool.hpp and scheduler.hpp

Fixed a few bugs and added pre-finalize callback functionalities.

Added deregistration features.

Added support for the Cereal serialization library.

Adds support for timeout in RPC calls (including for asynchronous calls).

Corrected a bug affecting finalize callbacks when the engine is initialized with an existing Margo instance.

Added the possibility to get the hg_addr_t underlying a thallium endpoint.