pkg: remove support for autoload (automatically loading package at start). * pkg.m, pkg/private/install.m, pkg/private/load_packages.m, pkg/private/rebuild.m: remove support for automatically loading packages. Having octave itself and the package manager automatically load packages is a bad idea. If a user wants to load a package at startup then it should specify it on its octaverc file. This can also be done on the system-wide octaverc file. This also simplifies pkg (this patch only removes code). * startup/version-rcfile: do not run 'pkg ("load", "auto")' at startup. * doc/interpreter/package.txi: remove mention of package autoload from the manual.

4a3a7c6111c880258a2da90ffbb9eb53e421529f gnulib-hg