This is a legacy commit from before 2015-03-01.
It may be incomplete as well as inconsistent.
See COPYING.legacy and README.history for details.

Removed advanceѕtime series input/output as presented in sffheaders.cc and
sffheaders.h and moved those files to a new library. These files strongly
depended on code in libtfxx which is undesired. The bilateral relationship
between libtfxx and libtsxx is most appropriately be resolved by introducing a
new library which depends on both, libtsxx and libtfxx.

After making libtsxx independent of libtfxx I was unable to make libtfxx
compile. This is due to libtfx file types being reimplemented in libtsxx
necessarily.

Side-effects:
- the modification started here, will change the library interfaces expected
  by time series filter and plot programs