Description:
------------
This is not a bug in PHP.  It is a problem in cURL but I am reporting it here as well to make life easier for people compiling PHP from source with cURL 7.21.5

Only when cURL 7.21.5 is installed from source

curl-config --version does not return a correct version number.  It returns a "-" instead of 7.21.5

./configure with --with-curl  stops with an error message saying that PHP needs cURL greater than 7.10.2 

The solution is to edit the    curl-config file  at around line 97

   --version)
     echo libcurl -
     exit 0
     ;;

Change 
   echo libcurl -
to
  echo libcurl 7.21.5