delta: add systemd-delta tool to find overriden configuration and unit files

.gitignore

@@ -1,3 +1,4 @@
+/systemd-delta
 /systemd-sleep
 /systemd-inhibit
 /systemd-remount-fs

Makefile.am

@@ -214,7 +214,8 @@ bin_PROGRAMS = \
 	systemd-cgtop \
 	systemd-stdio-bridge \
 	systemd-nspawn \
-	systemd-detect-virt
+	systemd-detect-virt \
+	systemd-delta
 
 dist_bin_SCRIPTS = \
 	src/analyze/systemd-analyze
@@ -452,6 +453,7 @@ MANPAGES = \
 	man/systemd.1 \
 	man/systemctl.1 \
 	man/systemd-cgls.1 \
+	man/systemd-delta.1 \
 	man/systemd-cgtop.1 \
 	man/systemd-nspawn.1 \
 	man/systemd-tmpfiles.8 \
@@ -1114,6 +1116,13 @@ systemd_detect_virt_SOURCES = \
 systemd_detect_virt_LDADD = \
 	libsystemd-shared.la
 
+# ------------------------------------------------------------------------------
+systemd_delta_SOURCES = \
+	src/delta/delta.c
+
+systemd_delta_LDADD = \
+	libsystemd-shared.la
+
 # ------------------------------------------------------------------------------
 systemd_getty_generator_SOURCES = \
 	src/getty-generator/getty-generator.c

TODO

@@ -23,6 +23,10 @@ Bugfixes:
 
 Features:
 
+* (attempt to) make Debianites happy:
+        - implement .d/ auto includes for unit files
+        - add syntax to reset ExecStart= lists (and similar)
+
 * actually queue the new default unit after switch-root
 
 * remove old root in switch-root logic