Each entry in specification_list points to a string
in the format XrmPutLineResource. following a call to XtAppSetFallbackResources,
when a resource database is being created for a particular screen and
the Intrinsics are not able to find or read an application-specific class
resource file and if specification_list is not NULL the resource specification
in specification_list will be merged into the screen resource database
in place of the application-specific class resource file. XtAppSetFallbackResources
is not required to copy specification_list; the caller must ensure that
the contents of the list and the strings addressed by the list remain valid
until all displys are initialized or until XtAppSetFallbackResources
is called again. The value NULL for specification_list removes any previous
fallback resource specification for the application context. The intended
use for fallback resources is to provide a minimal number of resources
that will amke the application usable (or at least terminate with helful
diagnostic messages) when some problem exists in finding and loading the
application defaults file.