Update documentation and images

doc/Jamfile

@@ -56,8 +56,8 @@ boostbook doc
         <xsl:param>chapter.autolabel=0
         <xsl:param>boost.image.src=images/beast.png
         <xsl:param>boost.image.alt="Beast Logo"
-        <xsl:param>boost.image.w=1007
-        <xsl:param>boost.image.h=107
+        <xsl:param>boost.image.w=2400
+        <xsl:param>boost.image.h=80
         <xsl:param>boost.root=$(broot)
         <xsl:param>chapter.autolabel=0
         <xsl:param>chunk.first.sections=1               # Chunk the first top-level section?

doc/http.qbk

@@ -222,7 +222,7 @@ When the implementation reads messages from a socket, it can read bytes lying
 after the end of the message if they are present (the alternative is to read
 a single byte at a time which is unsuitable for performance reasons). To
 store and re-use these extra bytes on subsequent messages, the read interface
-requires an additional paramter: a [link beast.types.DynamicBuffer [*`DynamicBuffer`]]
+requires an additional parameter: a [link beast.types.DynamicBuffer [*`DynamicBuffer`]]
 object. This example reads a message from the socket, with the extra bytes
 stored in the streambuf parameter for use in a subsequent call to read:
 ```