Remove patch for NetBSD to ride on Linux condition.

NetBSD condition exists since 2.8.11, and current linux condition part
including fenv.h, it does not exist on NetBSD<6 and  not usable except
arm, i386, sparc and x86_64 even on NetBSD-current.
restore ncurses dependency fix, it had been lost at updated to 2.8.12.
fixes i486 magic condition.
pkglint is written in perl; it should depend on perl and not just some
perl modules. (fix USE_TOOLS to have perl:run instead of just perl)
pkglint