Add doxygen group for rpmstring, include in librpm + hacking docs

doc/hacking/Doxyheader

@@ -54,3 +54,5 @@
  */
 /** \defgroup	rpmfileutil	File and Path Manipulation API.
  */
+/** \defgroup	rpmstring	String Manipulation API.
+ */

doc/librpm/Doxyheader

@@ -50,3 +50,5 @@
  */
 /** \defgroup	rpmfileutil	File and Path Manipulation API.
  */
+/** \defgroup	rpmstring	String Manipulation API.
+ */

rpmio/rpmstring.h

@@ -1,54 +1,89 @@
 #ifndef _RPMSTRING_H_
 #define _RPMSTRING_H_
 
-/** \file rpmio/rpmstring.h
- *
+/** \ingroup rpmstring
+ * \file rpmio/rpmstring.h
+ * String manipulation helper functions
  */
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
+/** \ingroup rpmstring
+ * Locale insensitive islower(3) 
+ */
 static inline int xislower(int c)  {
     return (c >= 'a' && c <= 'z');
 }
+
+/** \ingroup rpmstring
+ * Locale insensitive isupper(3)
+ */
 static inline int xisupper(int c)  {
     return (c >= 'A' && c <= 'Z');
 }
+
+/** \ingroup rpmstring
+ * Locale insensitive isalpha(3)
+ */
 static inline int xisalpha(int c)  {
     return (xislower(c) || xisupper(c));
 }
+
+/** \ingroup rpmstring
+ * Locale insensitive isdigit(3)
+ */
 static inline int xisdigit(int c)  {
     return (c >= '0' && c <= '9');
 }
+
+/** \ingroup rpmstring
+ * Locale insensitive isalnum(3)
+ */
 static inline int xisalnum(int c)  {
     return (xisalpha(c) || xisdigit(c));
 }
+
+/** \ingroup rpmstring
+ * Locale insensitive isblank(3)
+ */
 static inline int xisblank(int c)  {
     return (c == ' ' || c == '\t');
 }
+
+/** \ingroup rpmstring
+ * Locale insensitive isspace(3)
+ */
 static inline int xisspace(int c)  {
     return (xisblank(c) || c == '\n' || c == '\r' || c == '\f' || c == '\v');
 }
 
+/** \ingroup rpmstring
+ * Locale insensitive tolower(3)
+ */
 static inline int xtolower(int c)  {
     return ((xisupper(c)) ? (c | ('a' - 'A')) : c);
 }
+
+/** \ingroup rpmstring
+ * Locale insensitive toupper(3)
+ */
 static inline int xtoupper(int c)  {
     return ((xislower(c)) ? (c & ~('a' - 'A')) : c);
 }
 
-/** \ingroup rpmio
+/** \ingroup rpmstring
  * Locale insensitive strcasecmp(3).
  */
 int xstrcasecmp(const char * s1, const char * s2)		;
 
-/** \ingroup rpmio
+/** \ingroup rpmstring
  * Locale insensitive strncasecmp(3).
  */
 int xstrncasecmp(const char *s1, const char * s2, size_t n)	;
 
-/**
+/** \ingroup rpmstring
  * Split string into fields separated by a character.
  * @param str		string
  * @param length	length of string
@@ -57,13 +92,13 @@ int xstrncasecmp(const char *s1, const char * s2, size_t n)	;
  */
 char ** splitString(const char * str, int length, char sep);
 
-/**
+/** \ingroup rpmstring
  * Free split string argv array.
  * @param list		argv array
  */
 void freeSplitString( char ** list);
 
-/**
+/** \ingroup rpmstring
  * Remove occurences of trailing character from string.
  * @param s		string
  * @param c		character to strip
@@ -71,39 +106,39 @@ void freeSplitString( char ** list);
  */
 char * stripTrailingChar(char * s, char c);
 
-/**
+/** \ingroup rpmstring
  */
 typedef struct StringBufRec *StringBuf;
 
-/**
+/** \ingroup rpmstring
  */
 StringBuf newStringBuf(void);
 
-/**
+/** \ingroup rpmstring
  */
 StringBuf freeStringBuf( StringBuf sb);
 
-/**
+/** \ingroup rpmstring
  */
 void truncStringBuf(StringBuf sb);
 
-/**
+/** \ingroup rpmstring
  */
 char * getStringBuf(StringBuf sb);
 
-/**
+/** \ingroup rpmstring
  */
 void stripTrailingBlanksStringBuf(StringBuf sb);
 
-/**
+/** \ingroup rpmstring
  */
 #define appendStringBuf(sb, s)     appendStringBufAux(sb, s, 0)
 
-/**
+/** \ingroup rpmstring
  */
 #define appendLineStringBuf(sb, s) appendStringBufAux(sb, s, 1)
 
-/**
+/** \ingroup rpmstring
  */
 void appendStringBufAux(StringBuf sb, const char * s, int nl);