unify env variables and use DPRINTF (#89)

* unify handling of env variables

create a class containing all (most?) environment variables used by rocshmem and an object that is instatiated
before library_init, since some of the environment variables need to be
set before we start the bootstraping process.

This allows us to remove two files from the bootstrap directory.

* replace INFO and TRACE macros with DPRINTF

to be more consistent with the rest of the rocSHMEM code

src/reverse_offload/mpi_transport.cpp

@@ -590,6 +590,8 @@ std::unique_ptr<MPI_Request[]> MPITransport::raw_requests() {
 }
 
 void MPITransport::progress() {
+  static int progress_delay = rocshmem_env_.get_ro_progress_delay();
+
   if (requests.size() == 0) {
     const int tag{1000};
     int flag{0};
@@ -597,7 +599,7 @@ void MPITransport::progress() {
 
     // Slowing the progress engine down a bit avoid hammering the memory subsystem.
     // This leads to significant performance benefits
-    usleep (rocshmem_env_config.ro_progress_delay);
+    usleep (progress_delay);
     NET_CHECK(MPI_Iprobe(MPI_ANY_SOURCE, tag, ro_net_comm_world, &flag, &status));
   } else {
     DPRINTF("Testing all outstanding requests (%zu)\n", requests.size());