Fix online documentation URL.

config/checksrc/incorrect_mpi_abort_exitcode.c

config/checksrc/intelmpi_datatype.c

config/checksrc/mpich_unweighted_topo_comm_dup.c

config/checksrc/openmpi_datatype.c

config/checksrc/openmpi_dup.c

config/checksrc/openmpi_struct_dt.c

examples/Makefile.am

examples/idxlist_examples.c

examples/idxsection_examples.c

examples/print_index_list.h

examples/row2col.c

examples/row2col_f.f90

examples/rrobin.c

examples/tr_gp2fs.c

examples/unstruct_halo_exchange_f.f90

inst_headers/Makefile.am

inst_headers/f90/Makefile.am

perf/Makefile.am

perf/perf_idxsection_get_positions_of_indices.c

src/Makefile.am