Log Message:
viewvc: update to 1.2.0.

ViewVC 1.2.0 is a sort of interim release (and release line) intended
to be the last ViewVC release line that offers Python 2 support.
Rather than bundle into the next major post-1.1 release both the
switch to Python 3 plus all the ViewVC-1.1-incompatible changes
that have been baking unreleased for the past decade, we decided
to roll out those changes as ViewVC 1.2 without the Python 3 upgrade
bit.

ChangeLog:

    bumped minimum supported Python version to 2.4
    implemented support for property diffs (Tigris #383)
    allow user-configurable cvsgraph display (Tigris #336)
    allow rNNNN syntax for Subversion revision numbers (Tigris #441)
    display revision numbers in CVS tag/branch selector (Tigris #546)
    allow roots to have optional context (#58)
    use a more secure temporary file generator (#159)
    fix problems with make-database and special characters (#141, #182)
    fix bogus default ci_when value in cvsdb (#200)
    standalone query interface removed (#206)
    GUI support (--gui) removed from standalone.py