Hi,
the develserver is not a package that should be installed on the MLD system, but only needed on the develop PC. So, if you do a make in the develserver folder, this will start a webserver on the devel PC that are present all your packages for download by a MLD System.
So, after you have do a make you must setup the devel user (OPKG_DEVELOPER) on the MLD System in the rc.config. By default the username is the same as the user that has made the make on the devel PC.
After this you can do a "opkg update" and than you can install the packages you have build on your devel PC.
I hope you can follow my instructions. If not, feel free to ask again.
Claus