HaikuBook: fix warnings generated by Doxygen 1.18.16.

This version generates some warnings and identified some problems in our
documentation. It is also a bit more vigilant about undocumented elements, so
these are now decorated with a brief description. In the BNotification docs I
used a stray \p to create some whitespace between code and an image. This is
now fixed in the CSS instead.

docs/user/support/String.dox

@@ -636,18 +636,6 @@
 */
 
 
-/*!
-	\fn BString& BString::operator+=(const BString& string)
-	\brief Append the given \a string to the end of the BString.
-
-	\param string The string to append.
-
-	\return This method always returns \c *this.
-
-	\sa Append(const BString&, int32)
-*/
-
-
 /*!
 	\fn BString& BString::Append(const BString& string)
 	\brief Append the given \a string to the end of the BString.
@@ -1998,8 +1986,6 @@
 	\fn int32 BString::IFindFirst(const char* string) const
 	\brief Find the first occurrence of the given \a string case-insensitively.
 
-	\param string The \a string to search for.
-
 	\copydetails FindFirst(const char*) const
 */
 
@@ -2582,24 +2568,6 @@
 //! @{
 
 
-/*!
-	\fn char& BString::operator[](int32 index)
-	\brief Return a reference to the data at the given offset.
-
-	This function can be used to read a byte.
-	There is no bounds checking though, so make sure the \c index
-	you supply is valid.
-
-	\param index The index (zero-based) of the byte to get.
-
-	\return Returns a reference to the specified byte.
-
-	\sa ByteAt(int32 index) for a safer version.
-
-	\since BeOS R5
-*/
-
-
 /*!
 	\fn char BString::operator[](int32 index) const
 	\brief Returns the character in the string at the given offset.

docs/user/support/SupportDefs.dox

@@ -29,41 +29,49 @@
 
 /*!
 	\typedef typedef __haiku_int8 int8
+	\brief 1-byte signed integer.
 */
 
 
 /*!
 	\typedef typedef __haiku_uint8 uint8
+	\brief 1-byte unsigned integer.
 */
 
 
 /*!
 	\typedef typedef __haiku_int16 int16
+	\brief 2-bytes signed integer.
 */
 
 
 /*!
 	\typedef typedef __haiku_uint16 uint16
+	\brief 2-bytes unsigned integer.
 */
 
 
 /*!
 	\typedef typedef __haiku_int32 int32
+	\brief 4-bytes signed integer.
 */
 
 
 /*!
 	\typedef typedef __haiku_uint32 uint32
+	\brief 4-bytes unsigned integer.
 */
 
 
 /*!
 	\typedef typedef __haiku_int64 int64
+	\brief 8-bytes signed integer.
 */
 
 
 /*!
 	\typedef typedef __haiku_uint64 uint64
+	\brief 8-bytes unsigned integer.
 */
 
 
@@ -80,41 +88,49 @@
 
 /*!
 	\typedef typedef volatile int8 vint8
+	\brief 1-byte volatile signed integer.
 */
 
 
 /*!
 	\typedef typedef volatile uint8 vuint8
+	\brief 1-byte volatile unsigned integer.
 */
 
 
 /*!
 	\typedef typedef volatile int16 vint16
+	\brief 2-bytes volatile signed integer.
 */
 
 
 /*!
 	\typedef typedef volatile uint16 vuint16
+	\brief 2-bytes volatile unsigned integer.
 */
 
 
 /*!
 	\typedef typedef volatile int32 vint32
+	\brief 4-bytes volatile signed integer.
 */
 
 
 /*!
 	\typedef typedef volatile uint32 vuint32
+	\brief 4-bytes volatile unsigned integer.
 */
 
 
 /*!
 	\typedef typedef volatile int64 vint64
+	\brief 8-bytes volatile signed integer.
 */
 
 
 /*!
 	\typedef typedef volatile uint64 vuint64
+	\brief 8-bytes volatile unsigned integer.
 */
 
 
@@ -131,41 +147,49 @@
 
 /*!
 	\typedef typedef volatile long vlong
+	\brief Volatile signed long.
 */
 
 
 /*!
 	\typedef typedef volatile int vint
+	\brief Volatile signed int.
 */
 
 
 /*!
 	\typedef typedef volatile short vshort
+	\brief Volatile signed short.
 */
 
 
 /*!
 	\typedef typedef volatile char vchar
+	\brief Volatile signed char.
 */
 
 
 /*!
 	\typedef typedef volatile unsigned long vulong
+	\brief Volatile unsigned long.
 */
 
 
 /*!
 	\typedef typedef volatile unsigned int vuint
+	\brief Volatile unsigned int.
 */
 
 
 /*!
 	\typedef typedef volatile unsigned short vushort
+	\brief Volatile unsigned short.
 */
 
 
 /*!
 	\typedef typedef volatile unsigned char vuchar
+	\brief Volatile unsigned char.
 */
 
 
@@ -181,12 +205,14 @@
 
 
 /*!
-  \typedef typedef unsigned char uchar
+	\typedef typedef unsigned char uchar
+	\brief Unsigned 1-byte wide character.
 */
 
 
 /*!
-  \typedef typedef unsigned short unichar
+	\typedef typedef unsigned short unichar
+	\brief Unsigned 2-byte wide character.
 */