If the package contains files called PKG_ADD or PKG_DEL
the commands in these files will be executed when the package is
added or removed from the users path. In some situations such files
are a bit cumbersome to maintain, so the package manager supports
automatic creation of such files. If a source file in the package
contains a PKG_ADD or PKG_DEL directive they will be
added to either the PKG_ADD or PKG_DEL files.
In m-files a PKG_ADD directive looks like this
## PKG_ADD: some_octave_command
Such lines should be added before the function keyword.
In C++ files a PKG_ADD directive looks like this
// PKG_ADD: some_octave_command
In both cases some_octave_command should be replaced by the
command that should be placed in the PKG_ADD file.
PKG_DEL directives work in the same way, except the
PKG_ADD keyword is replaced with PKG_DEL and the commands
get added to the PKG_DEL file.