HDF5Export: fix bug with hdf5-1.14.1 and local dir

When dls_view is started from local dir (i.e. no -d or DATADIR), the Group name in HD5 Export will end with ".", which freaks HD5 out and you get an exception:

  #000: H5G.c line 231 in H5Gcreate2(): unable to synchronously create group
    major: Symbol table
    minor: Unable to create file
  #001: H5G.c line 184 in H5G__create_api_common(): unable to create group
    major: Symbol table
    minor: Unable to initialize object
  #002: H5VLcallback.c line 4442 in H5VL_group_create(): group create failed
    major: Virtual Object Layer
    minor: Unable to create file
  #003: H5VLcallback.c line 4409 in H5VL__group_create(): group create failed
    major: Virtual Object Layer
    minor: Unable to create file
  #004: H5VLnative_group.c line 103 in H5VL__native_group_create(): unable to create group
    major: Symbol table
    minor: Unable to initialize object
  #005: H5Gint.c line 274 in H5G__create_named(): unable to create and link to group
    major: Symbol table
    minor: Unable to initialize object
  #006: H5Lint.c line 516 in H5L_link_object(): unable to create new link to object
    major: Links
    minor: Unable to initialize object
  #007: H5Lint.c line 759 in H5L__create_real(): can't insert link
    major: Links
    minor: Unable to insert object
  #008: H5Gtraverse.c line 836 in H5G_traverse(): internal path traversal failed
    major: Symbol table
    minor: Object not found
  #009: H5Gtraverse.c line 753 in H5G__traverse_real(): traversal operator failed
    major: Symbol table
    minor: Can't move to next iterator location
  #010: H5Lint.c line 551 in H5L__link_cb(): name already exists
    major: Links
    minor: Object already exists
terminate called after throwing an instance of 'H5::GroupIException'

We fix it by removing trailing "." and also, do not know if necessary, remove an extra trailing "/" if path is empty.

Signed-off-by: Matthias Schoepfer m.schoepfer@rethinkrobotics.com