Use a single marshal file for entire project

.gitignore

@@ -41,10 +41,10 @@ osx/Info.plist
 data/pkgconfig/hexchat-plugin.pc
 data/misc/hexchat.appdata.xml
 src/common/dbus/example
-src/common/dbus/marshallers.h
 src/common/dbus/org.hexchat.service.service
 src/common/dbus/remote-object-glue.h
 src/common/make-te
+src/common/marshal.*
 src/common/textenums.h
 src/common/textevents.h
 src/fe-gtk/hexchat