deprecated all discouraged functions

* libguile/Makefile.am:
* libguile/discouraged.c: Remove discouraged.c.

* libguile/deprecated.c:
* libguile/deprecated.h:
* libguile/discouraged.h: All functions and declarations moved from
  discouraged.[ch] to deprecated.[ch], adding deprecation warnings.

* libguile/init.c: Remove discouraged init.

* libguile/numbers.c (scm_num2float, scm_num2double): Deprecate.

* test-suite/standalone/test-num2integral.c: Port to modern API.

libguile/Makefile.am

@@ -128,7 +128,6 @@ libguile_@GUILE_EFFECTIVE_VERSION@_la_SOURCES =				\
 	debug.c					\
 	deprecated.c				\
 	deprecation.c				\
-	discouraged.c				\
 	dynwind.c				\
 	eq.c					\
 	error.c					\
@@ -230,7 +229,6 @@ DOT_X_FILES =					\
 	debug.x					\
 	deprecated.x				\
 	deprecation.x				\
-	discouraged.x				\
 	dynl.x					\
 	dynwind.x				\
 	eq.x					\
@@ -330,7 +328,6 @@ DOT_DOC_FILES = 				\
 	debug.doc				\
 	deprecated.doc				\
 	deprecation.doc				\
-	discouraged.doc				\
 	dynl.doc				\
 	dynwind.doc				\
 	eq.doc					\