Document new brmember features.

doc/mbase.md

@@ -251,6 +251,17 @@ Returns the number of months this member is suspended in
 ```(*current-month*)```. If the member is not suspended, returns
 ```0```.
 
+    ((brmember-suspended-for at-least [less-than]) mr)
+
+* ```at-least``` - number of months
+* ```less-than``` - number of months
+* ```mr``` - member record structure
+
+Curried predicate for checking whether given member ```mr``` is at
+least ```at-least``` months suspended. If ```less-than``` is provided
+then only those records which have been suspended less than this value
+are included.
+
     (brmember<? a b)
 
 * ```a``` - a member record structure
@@ -267,6 +278,14 @@ the lexicographical order.
 Adds (prepends) given transaction ```pt``` to given member record
 ```mr```'s ```'payments'``` key list.
 
+    (brmember-credit mr)
+
+* ```mr``` - a member record structure
+
+Returns the total credit manually recorded in given member
+record. Takes into account ```(*current-month*)``` to allow showing
+current status at given date.
+
     (brmember-payments mr)
 
 * ```mr``` - a member record structure