packaging: fix names of dh files

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>

diff --git a/debian/hippotat-doc.install b/debian/hippotat-common.install
similarity index 100%
rename from debian/hippotat-doc.install
rename to debian/hippotat-common.install

diff --git a/debian/hippotat.postinst b/debian/hippotat-common.postinst
similarity index 100%
rename from debian/hippotat.postinst
rename to debian/hippotat-common.postinst

diff --git a/debian/hippotat.postrm b/debian/hippotat-common.postrm
similarity index 100%
rename from debian/hippotat.postrm
rename to debian/hippotat-common.postrm

diff --git a/debian/hippotatd.hippotatd.init b/debian/hippotat-server.hippotatd.init
similarity index 100%
rename from debian/hippotatd.hippotatd.init
rename to debian/hippotat-server.hippotatd.init