TNG version 1.7.3

TNG version 1.7.3

Corresponds to commit e862ebe8 in the TNG repository.

Large parts of the TNG code have been rewritten to avoid code duplication. Some functions have been combined.

Summary of additional changes (see git log for full details):
  Bug fixes:
    Fixed bug reading last frame and time of last frame.
    Fix MingW build
    Fixed bug reading non-particle data.
    Check that ZLib is available before using it.
    Fixed bug when appending to trajectory.

  New functions:
    tng_util_num_frames_with_data_of_block_id_get()

  Fixed compiler warnings
  Improved testing suite

Change-Id: I97334b1d93f21646fe1625e65e5fcdf38a0450d9