part framework not sessions friendly in certain cases

[hppritcha]

I've been using --enable-mca-dso config option with main to help debug some problems and discovered in the process that the framework doesn't work in a sessions multi init/finalize use case:

[er-head:1037963] *** Process received signal ***
[er-head:1037963] Signal: Segmentation fault (11)
[er-head:1037963] Signal code: Address not mapped (1)
[er-head:1037963] Failing at address: 0x7fffebdfa260
[er-head:1037963] [ 0] /lib64/libpthread.so.0(+0x12cf0)[0x7ffff7765cf0]
[er-head:1037963] [ 1] /lib64/libc.so.6(+0xcbe67)[0x7ffff7459e67]
[er-head:1037963] [ 2] /home/hpritchard/ompi-er2/install_main/lib/libmpi.so.0(mca_part_base_select+0x172)[0x7ffff7ad7289]
[er-head:1037963] [ 3] /home/hpritchard/ompi-er2/install_main/lib/libmpi.so.0(+0x863d9)[0x7ffff79f93d9]
[er-head:1037963] [ 4] /home/hpritchard/ompi-er2/install_main/lib/libmpi.so.0(ompi_mpi_instance_init+0x72)[0x7ffff79f99bc]
[er-head:1037963] [ 5] /home/hpritchard/ompi-er2/install_main/lib/libmpi.so.0(MPI_Session_init+0x1dd)[0x7ffff7a76982]
[er-head:1037963] [ 6] ./hello_sessions_c[0x40078d]
[er-head:1037963] [ 7] /lib64/libc.so.6(__libc_start_main+0xe5)[0x7ffff73c8d85]
[er-head:1037963] [ 8] ./hello_sessions_c[0x40068e]
[er-head:1037963] *** End of error message ***