C node needs DFLAG_DIST_MONITOR flag set when connecting,
and support for processing monitoring start/end messages
received from counterpart, to make global registration
actually work.

Make erl_interface build on VxWorks

* sv/serge-new_float_ext:
  Let ei_get_type() return ERL_FLOAT_EXT instead of NEW_FLOAT_EXT
  Fix ei_tmo to restrict dflags to NEW_FLOAT_EXT
  compact IEEE 754 double encoding in external binary format for ei
  fix typo in ei_decode_ei_term documentation

OTP-8684 sv/serge-new_float_ext

compact IEEE 754 double encoding in external binary format for ei

Implement the compact IEEE 754 double encoding in external binary format
for ei. Encoding for ei now always produces the NEW_FLOAT_EXT format.
Decoding and term printing handle both the old ERL_FLOAT_EXT encoding and
the new NEW_FLOAT_EXT encoding. 

Legacy erl_interface code also handles the new encoding, but still produces
the ERL_FLOAT_EXT encoding by default.

Also enable the DFLAG_NEW_FLOATS distribution flag.

ei_get_type() will return ERL_FLOAT_EXT regardless if the external format
is encoded with ERL_FLOAT_EXT or NEW_FLOAT_EXT for doubles.

Reduce the number of copies of the code for encoding and decoding doubles
throughout ei and erl_interface by instead calling the ei encoding and
decoding functions wherever possible.

Restore commented-out float tests in ei_decode_SUITE and ei_encode_SUITE in
lib/erl_interface/test. Modify them to make them match the style of other
tests in the same suites.

These changes are based on an ei float patch from Serge Aleynikov
originally submitted against R12B-2 in July 2008 and reworked by Steve
Vinoski May 2010.

Implement the compact IEEE 754 double encoding in external binary
format for ei. Encoding for ei now always produces the NEW_FLOAT_EXT
format. Decoding and term printing handle both the old ERL_FLOAT_EXT
encoding and the new NEW_FLOAT_EXT encoding. Legacy erl_interface code
also handles the new encoding, but still produces the ERL_FLOAT_EXT
encoding by default.

Also enable the DFLAG_NEW_FLOATS distribution flag.

Reduce the number of copies of the code for encoding and decoding
doubles throughout ei and erl_interface by instead calling the ei
encoding and decoding functions wherever possible.

Restore commented-out float tests in ei_decode_SUITE and
ei_encode_SUITE in lib/erl_interface/test. Modify them to make them
match the style of other tests in the same suites.

These changes are based on an ei float patch from Serge Aleynikov
originally submitted against R12B-2 in July 2008.

          Debug trace output for connection activity could be enabled
          setting the trace level as an integer to the EI_TRACELEVEL
          environment variable. This option could also be read and set from
          a running program using ei_get_tracelevel(void) and
          ei_set_tracelevel(int).