fix changelog filename is various source files

Makefile.am

 # vi: noexpandtab softtabstop=0
 ## Process this file with automake to produce Makefile.in
 
-EXTRA_DIST = FAQ.md README.md COPYING AUTHORS INSTALL.md NEWS ChangeLog \
+EXTRA_DIST = FAQ.md README.md COPYING AUTHORS INSTALL.md NEWS CHANGELOG.md \
              backupninja.spec backupninja.spec.in autogen.sh
 
 SUBDIRS = etc examples handlers lib man src

RELEASE.md

@@ -17,7 +17,7 @@ Upstream
 
 * commit, tag and create the tarball:
 
-        git commit configure.ac ChangeLog \
+        git commit configure.ac CHANGELOG.md \
             -m "Releasing backupninja $VERSION" && \
         git clean -fdx && \
         git tag -s "backupninja-$VERSION" \

backupninja.spec.in

@@ -50,7 +50,7 @@ rm -fr %{buildroot}
 
 %ghost %{_localstatedir}/log/backupninja.log
 
-%doc AUTHORS COPYING ChangeLog INSTALL.md NEWS README.md
+%doc AUTHORS COPYING CHANGELOG.md INSTALL.md NEWS README.md
 %{_mandir}/man1/*
 %{_mandir}/man5/*