* This resolves must lintian warnings and errors.

* Added a Freedesktop file - only as part of the debian package yet.
  `make install` won't install a Desktop file since it would have to be
  generated.
* Just like when installing manually, you can have a Curses and Gtk installation
  side by side using the same .teco_ini.
* Common data between the Curses UI (sciteco-curses) and Gtk UI are in a new
  architecture-independant package sciteco-common.
* The Gtk+ binaries are prefixed with `g` (gsciteco, gtedoc.tes, ggrosciteco.tes).
* Debian source and binary packages can be built using `./distribute.mk debian`
  as usual.
  It should also be possible to push everything to the PPA for the next release,
  although that is not yet tested.

* required a new changelog entry since the target release is now v2.0.0
* Glib dependency bumped

 * it was necessary to increase the upstream version so I could
   upload new versions to launchpad while debugging PPA build issues.
 * ChangeLog finalized for v0.6.4
 * SciTECO requires at least libglib v2.28 (but that's only a guess)

 * distributed binary packages are standard debian packages
 * ./distribute might fix up the package version and branch for Ubuntu/PPA

 * prepared for upload to Ubuntu PPA
 * debian package will not be in autoconf source distro
 * will only build as a non-native package based on a source bundle
   that contains scintilla, scinterm and has patches applied