I have removed the "default" pointer from the cmd_line_args,
because it really wasn't used except by WTTS. It now is called
wtts_string to make this explicit, and most variables have it
set to WTTS_USE_DEFAULT, so the default is output automatically.

The variables such as star[x].mass, separation, metallicity, etc.
which were set directly in cmd_line_args.h are now replaced by
preferences->xyz variables, which are then copied to the appropriate
locations. This means there is a more logical setup with the command
line args only setting preferences options, rather than random other
parts of the code.

The new function set_defaults() should be used to set the default
parameters in preferences. The "list_args" now uses these.

Fixed a bug in configure where binary_c_version_macros.h had the wrong
ifndef ... endif macros, clashing with binary_c_version.h.

Added the patch number as a macro, so version numbers like 2.1.1
are now valid.

Added the major, minor and patch number macros to version.c

Also synced the latest libmemoize and librinterpolate.

Fixed a memory leak in the discs code, and its interaction with
libmemoize, which only manifests itself when an existing disc
is appended. A call to free the memoize data before doing this
fixes the problem.