a) index_expire was overwritten during interactive-reconfigure;

b) new configuration variables:

     expire_old_builds - controls new functionality (persistent state
                         for "we already tested this distribution");

     test_uptodate and install_uptodate:

                       - control whether one should ignore
                         test/install requests for
                         modules/distributions/bundles which are known
                         to be uptodate;

        The default is the same as now: test always, install
        distributions and bundles.  The value is a string; if contains
        words modules distributions bundles, this causes effect on the
        corresponding operation.

c) New command `install_tested'.  Runs `install' over distributions
   which are in "persistently known to be tested" state.

d) Fixes bugs with the "put ./blib of tested in this session, but
   uninstalled distributions to @INC when working with a distribution"
   logic.  I do not know how logic of interaction of PERL5LIB with
   PERLLIB worked before (due to coincidence only?).  Moreover, the
   changes were not done during Makefile.PL'ing, and during `make';
   only during `make test'.

   Moreover, the algorithm of finding missing prerequisites was not
   taking into account those already tested distributions.  Fixed.
   Now one can reliably test large bundles (mine is of about 100
   distributions) without doing `make install'.

e) Special commands to `o conf' are printed with distinguishing indent;

f) The logic of persistent "tested-ok" state is the following one:
   distributions which were ever tested_ok are indexed in ./Metadata
   hash, with values being the build-directories.  [One could use glob
   '*/.cpantok' instead...]  When we need to test a distribution, we
   check the build directory for this file.  The file serves two
   purposes: first of all, it is a timestamp; we check that no
   modification was done to any file after this timestamp.  Second, it
   is a snapshot of the version of Perl used to test this directory;
   we check that it coincides with the snapshot of "this perl".

   If both tests pass, we check the configuration variable
   expire_old_builds; if the test was recent enough, we declare test
   successful without any further operation with the distribution.

   [Currently the snapshot consists of sitearchexp, the name of the
   perl executable (and a DLL if found), and the modification times of
   the latters.  The format may be changed at any time without
   negative sideeffects (except re-test).]

One important side effect of c+d+f: one can now make

    test Bundle::Foo

over a giant bundle without being a superuser; then do

    sudo perl -MCPAN -wle 'install Bundle::Foo'

or

    sudo perl -MCPAN -wle 'install_tested'

[no tests are actually run with the second invocation; the first one
will retest things which were not successfully completed during `test
Bundle::Foo'.]

g) One can keep patches in the directory $CPANROOT/patches.  The
   patches should be named diff_$name; here $name is the name of the
   subdirectory of $CPANROOT/build/.  [I could not make the logic of
   saving the output of the patching step in a file - I need 2>&1, and
   I do not know how to produce this portably.]

h) New method ->containsdists() which works over all 3 kinds of
   objects.  [Unfortunately, it does not take into account
   dependencies of modules.  AFAIK, there is not such information
   stored in the CPAN index.  Maybe we should store it in a local
   database?]
