Merged changes into HEAD from REXML 3.1.5.

The list of bug fixes/enhancements is at:

  http://www.germane-software.com/projects/rexml/query?status=closed&milestone=3.1.5


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@10888 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

lib/rexml/functions.rb

@@ -326,8 +326,8 @@ module REXML
       else
         str = string( object )
         #puts "STRING OF #{object.inspect} = #{str}"
-        if str =~ /^\d+/
-          object.to_s.to_f
+        if str =~ /^-?\.?\d/
+          str.to_f
         else
           (0.0 / 0.0)
         end