clamav: Add 0.90.2 version, remove older versions plus a number of other

clamav: Add 0.90.2 version, remove older versions plus a number of other
changes:
* Remove 0.88.6
* Added 0.90.2
* Add a new clamav-conf package to hold clamd.conf. This is needed by
  both clamd and freshclam and previously you needed to install clamd
  even if you didn't want it just to get freshclam to work.
* Assume that /var/lib is non-volatile. Move the virus database there
  by default.
* Update configuration files for the new 0.9x syntax.
* Simplify the init scripts.
* Indicate the freshclam also provides clamav data, so if you install
  freshclam you don't need data.
* NOTE: There are incompatible changes to libclamav in this release,
  anything that links directly against the library will need to be
  updated.