two API functions weren't in the .h and weren't documented (#3560)

Author: ramcdougal

docs/capi.rst

@@ -380,6 +380,20 @@ Sections
     checks for inactive Sections and removes them (they are not returned).
     Only after there are no references to a deleted Section will its memory be freed.
 
+.. c:function:: void nrn_section_ref(Section* sec)
+
+    Increase the Section's reference count. Sections with active references will
+    not be free'd from memory.
+
+    :param sec: Pointer to the Section to reference.
+
+.. c:function:: void nrn_section_unref(Section* sec)
+
+    Decrease the Section's reference count. Sections with active references will
+    not be free'd from memory.
+
+    :param sec: Pointer to the Section to unreference.
+
 .. c:function:: Section* nrn_cas(void)
 
     Get the currently accessed Section (top of the Section stack).

src/nrniv/neuronapi.h

@@ -55,6 +55,8 @@ void nrn_mechanism_insert(Section* sec, const Symbol* mechanism);
 nrn_Item* nrn_allsec(void);
 nrn_Item* nrn_sectionlist_data(const Object* obj);
 bool nrn_section_is_active(const Section* sec);
+void nrn_section_ref(Section* sec);
+void nrn_section_unref(Section* sec);
 Section* nrn_cas(void);
 
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