When calling validate() python function, TypeError exception was thrown
("argument list must be a tuple"), because the call does not have
arguments, and python does not accept empty tuple for execution. NULL
must be used instead, which was handled as argument construction failure
previously.
Storing them as "tuple" instead of "set", so they have a fix order.
This makes the output of the list() example stable. ("set" is printed out
in random order)
IO/Group/Policy Python API version is displayed instead of sudo version,
because that is not very meaningful in this context.
They are only displayed in verbose mode.
Example plugins express it more concrete that they are displaying their
version, not the API version.
If the plugin fails to open the file for writing, constructor will raise
an exception and exit before creating the "_log" member variable.
So the destructor will also raise a backtrace. (Which python ignores, but
dumps out to stderr.)
Examples are installed by default to "docdir", which refers to
PACKAGE_TARNAME variable which was empty for the python plugin Makefile.in
So the examples were installed to '.../share/doc/examples' instead
of '.../share/doc/sudo/examples'. This also made them be skipped from the
package.
Also the install target now depends on install-doc so the examples
gets installed also (similarly as other examples).
If non root can alter any imported python modules, he is able to run
anything he would like to as root user.
This class is a helper to avoid such situation.
This feature can be disabled with 'DeveloperMode=1' plugin option.
