config: move the "build shared libraries" option to the OS menu
The "Build shared libraries" config option is dependant on the type of
"Target OS".
Moving this options to the "Target OS" sub-menu is also better in the user
perspective: he/she no longer needs to go back and forth to see if he/she
missed any option.
1 This is NOT the official version of dialog. This version has been
2 significantly modified from the original. It is for use by the Linux
3 kernel configuration script. Please do not bother Savio Lam with