Add support for building RPM with Tito (#9)

Hand edited after being created by command:

/usr/bin/tito tag --use-version=4.0.1 --use-release=1

.tito/packages/.readme

@@ -0,0 +1,3 @@
+the .tito/packages directory contains metadata files
+named after their packages. Each file has the latest tagged
+version and the project's relative directory.

.tito/packages/xephem

@@ -0,0 +1 @@
+4.0.1-1 ./

.tito/tito.props

@@ -0,0 +1,5 @@
+[buildconfig]
+builder = tito.builder.Builder
+tagger = tito.tagger.VersionTagger
+changelog_do_not_remove_cherrypick = 0
+changelog_format = %s (%ae)

xephem.spec

@@ -0,0 +1,51 @@
+Name:		xephem
+Version:	4.0.1
+Release:        1
+Summary:        XEphem is an interactive astronomy program for all UNIX platforms.
+License:	MIT
+
+URL:            https://github.com/XEphem/XEphem
+
+Source0:        %{name}-%{version}.tgz
+
+BuildRequires:  gcc
+BuildRequires:  make
+BuildRequires:	motif-devel
+
+Requires:	motif
+
+%description
+XEphem is an interactive astronomy program for all UNIX platforms. Originally
+written by Elwood Downey in the 1990s, it has graciously been released under the
+MIT License. It is now maintained by an "XEphem" organization, with its source
+code residing at https://github.com/XEphem/XEphem.
+
+%if 0%{?rhel} >= 7
+%global motifl %{_libdir}
+%endif
+
+%prep
+%setup -q
+
+%build
+cd GUI/xephem
+make MOTIFL=%{motifl}
+gzip -c %{name}.man > %{name}.1x.gz
+
+%install
+mkdir -p %{buildroot}/%{_bindir}
+mkdir -p %{buildroot}/%{_mandir}/man1x/
+
+cd GUI/xephem
+install -m 0755 %{name} %{buildroot}/%{_bindir}
+install -m 0444 %{name}.1x.gz %{buildroot}/%{_mandir}/man1x/
+
+%files
+%{_bindir}/%{name}
+%{_mandir}/man1x/%{name}.1x.gz
+
+%changelog
+* Fri Mar 05 2021 Douglas Needham <cinnion+github@gmail.com> 4.0.1-1
+- New RPM package built with tito
+
+