Always include all sub directories in "make dist"
  Removed incorrect comment
configure.in:
  Unconditionally list make files in AC_CONFIG_FILES
  Removed 'thread_dirs', it is not used
  Minor cleanup
compile-dist:
  Simplified the configure line needed for "make dist" to get it all
zlib.m4, ssl.m4:
  Unconditionally list make files in AC_CONFIG_FILES
Makefile.am:
  Removed DIST_SUBDIRS not needed
  Don't copy soft links as files into source package