* work around a crash when using seledctions with BP
  read method. Selections are necessary for FLEXPATH.
  See ADIOS issue #154 for more info

* fix our use of ADIOS integer types. adios_long is
  always 64 bits, while adios_integer is always 32 bits.
  Thus when we encounter a C long we need to check its
  size and select the right ADIOS type. See ADIOS
  issue #153 for more info