Split and sort the list of EXTRA_DIST files

Makefile.am

@@ -6,9 +6,18 @@ aclocal_DATA = hamlib.m4
 pkgconfigdir = $(libdir)/pkgconfig
 pkgconfig_DATA = hamlib.pc
 
-EXTRA_DIST = PLAN LICENSE hamlib.m4 hamlib.pc.in README.md README.developer \
-	README.betatester README.freqranges README.multicast README.osx \
-	Android.mk
+EXTRA_DIST = \
+	Android.mk \
+	README.betatester \
+	LICENSE \
+	PLAN \
+	README.developer \
+	README.freqranges \
+	README.md \
+	README.multicast \
+	README.osx \
+	hamlib.m4 \
+	hamlib.pc.in
 
 doc_DATA = ChangeLog COPYING COPYING.LIB LICENSE \
 	README.md README.betatester README.developer