add misc documentation/notes

git-svn-id: svn+ssh://svn.gnucash.org/repo/gnucash/trunk@9620 57a11ea4-9604-0410-9ed3-97b8803252fd

src/business/business-core/gncBillTerm.c

@@ -55,6 +55,8 @@
 struct _gncBillTerm 
 {
   QofInstance     inst;
+
+  /* 'visible' data fields directly manipulated by user */
   char *          name;
   char *          desc;
   GncBillTermType type;
@@ -63,6 +65,7 @@ struct _gncBillTerm
   gnc_numeric     discount;
   gint            cutoff;
 
+  /* Internal management fields */
   /* See src/doc/business.txt for an explanation of the following */
   /* Code that handles this is *identical* to that in gncTaxTable */
   gint64          refcount;
@@ -572,6 +575,7 @@ gboolean gncBillTermIsDirty (GncBillTerm *term)
 
 /* Based on the timespec and a proximo type, compute the month and
  * year this is due.  The actual day is filled in below.
+ * XXX explain this, the logic is totally opaque to me.
  */
 static void
 compute_monthyear (GncBillTerm *term, Timespec post_date,
@@ -604,6 +608,8 @@ compute_monthyear (GncBillTerm *term, Timespec post_date,
   if (year) *year = iyear;
 }
 
+/* XXX explain this, the logic is totally opaque to me. */
+
 static Timespec
 compute_time (GncBillTerm *term, Timespec post_date, int days)
 {

src/business/business-core/gncBillTerm.h

@@ -42,8 +42,9 @@ typedef struct _gncBillTerm GncBillTerm;
 #define GNC_BILLTERM(obj)     (QOF_CHECK_CAST((obj), GNC_ID_BILLTERM, GncBillTerm))
 
 /*
- *  How to interpret the amount.
+ * How to interpret the amount.
  * You can interpret it as a VALUE or a PERCENT.
+ * ??? huh?
  */
 typedef enum {
   GNC_TERM_TYPE_DAYS = 1,

src/business/business-core/gncBusPeriod.c

@@ -1,4 +1,5 @@
 
+
 XXX TODO:
 -- contemplate a per-colection (per type) edit/commmit-edit, 
    clone, dirty, etc. functions some more ...