Add Doxygen headers for mdbcommon utilities

mdbcommon/lookupa.c

@@ -1,11 +1,11 @@
-/*
-  --------------------------------------------------------------------
-  lookupa.c, by Bob Jenkins, December 1996. Public Domain.  No warranty.
-  Source is http://burtleburtle.net/bob/c/lookupa.c
-  Customized for elegant for both 32 and 64 bits machines by Yusong Wang,
-  May, 2007.
-  --------------------------------------------------------------------
-*/
+/**
+ * @file lookupa.c
+ * @brief Jenkins lookup hash functions for 32- and 64-bit machines.
+ *
+ * Based on public domain code by Bob Jenkins (December 1996), sourced from
+ * http://burtleburtle.net/bob/c/lookupa.c. Customized for elegant for both
+ * 32- and 64-bit machines by Yusong Wang (May 2007). Public domain; no warranty.
+ */
 #ifndef STANDARD
 #  include "standard.h"
 #endif

mdbcommon/lsfp.c

@@ -1,8 +1,11 @@
 
-/* routine: lsfp()
- * purpose: compute nth order polynomial least squares, using only specified
- *          terms.
- * 
+/**
+ * @file lsfp.c
+ * @brief Polynomial least squares fit using specified terms.
+ *
+ * Implements the `lsfp` routine that computes an nth order polynomial
+ * least squares fit using only the terms requested by the caller.
+ *
  * Michael Borland, 1986.
  */
 #include "matlib.h"

mdbcommon/recycle.c

@@ -1,17 +1,12 @@
-/*
-  --------------------------------------------------------------------
-  By Bob Jenkins, September 1996.  recycle.c
-  You may use this code in any way you wish, and it is free.  No warranty.
-
-  This manages memory for commonly-allocated structures.
-  It allocates RESTART to REMAX items at a time.
-  Timings have shown that, if malloc is used for every new structure,
-  malloc will consume about 90% of the time in a program.  This
-  module cuts down the number of mallocs by an order of magnitude.
-  This also decreases memory fragmentation, and freeing structures
-  only requires freeing the root.
-  --------------------------------------------------------------------
-*/
+/**
+ * @file recycle.c
+ * @brief Memory recycling routines for frequently allocated structures.
+ *
+ * Provides functions that manage pools of reusable memory blocks to
+ * reduce malloc overhead and memory fragmentation. Written by Bob
+ * Jenkins (September 1996) and released to the public domain with no
+ * warranty.
+ */
 
 #ifndef STANDARD
 #  include "standard.h"