New in 5.18.14 - July 2018

* several configury fixes to enable cross platform building.
* fompletion of a change in "char-mapper" to enable bootstrapping
* Guile 1.8 support was removed
* Replace AG_SCM_STR02SCM with scm_from_latin1_string
  this breaks Guile 1.8.
* adaptations for cross compiling
* no more generating autoconf macros
* fix internal implementation of forking off autogen in xml2ag
* when calling abort() causes problems, exit() can now be
  called (via an option) instead.
* add support for nanosecond precision in file times
* suppress dumb warnings about embedded NUL bytes in formats.
