Improve client/daemon xdg/systemd experience

* Makefile.in: Add emacsclient.desktop generation.
* etc/emacsclient.desktop: Add file, use emacsd as StartupWMClass.
* etc/emacs.service: Run with name emacsd (bug#37847).

Makefile.in

@@ -714,6 +714,13 @@ install-etc:
 	  ${srcdir}/etc/emacs.desktop > $${tmp}; \
 	${INSTALL_DATA} $${tmp} "$(DESTDIR)${desktopdir}/${EMACS_NAME}.desktop"; \
 	rm -f $${tmp}
+	tmp=etc/emacsclient.tmpdesktop; rm -f $${tmp}; \
+	client_name=`echo emacsclient | sed '$(TRANSFORM)'`${EXEEXT}; \
+	sed -e "/^Exec=emacsclient/ s|emacsclient|${bindir}/$${client_name}|" \
+	  -e "/^Icon=emacs/ s/emacs/${EMACS_NAME}/" \
+	  ${srcdir}/etc/emacsclient.desktop > $${tmp}; \
+	${INSTALL_DATA} $${tmp} "$(DESTDIR)${desktopdir}/$${client_name}.desktop"; \
+	rm -f $${tmp}
 	umask 022; ${MKDIR_P} "$(DESTDIR)${appdatadir}"
 	tmp=etc/emacs.tmpappdata; rm -f $${tmp}; \
 	sed -e "s/emacs\.desktop/${EMACS_NAME}.desktop/" \

etc/emacs.service

@@ -8,7 +8,7 @@ Documentation=info:emacs man:emacs(1) https://gnu.org/software/emacs/
 
 [Service]
 Type=notify
-ExecStart=emacs --fg-daemon
+ExecStart=@emacs emacsd --fg-daemon
 ExecStop=emacsclient --eval "(kill-emacs)"
 # The location of the SSH auth socket varies by distribution, and some
 # set it from PAM, so don't override by default.

etc/emacsclient.desktop

@@ -0,0 +1,12 @@
+[Desktop Entry]
+Name=Emacs (Client)
+GenericName=Text Editor
+Comment=Edit text
+MimeType=text/english;text/plain;text/x-makefile;text/x-c++hdr;text/x-c++src;text/x-chdr;text/x-csrc;text/x-java;text/x-moc;text/x-pascal;text/x-tcl;text/x-tex;application/x-shellscript;text/x-c;text/x-c++;
+Exec=emacsclient -c %F
+Icon=emacs
+Type=Application
+Terminal=false
+Categories=Development;TextEditor;
+StartupWMClass=Emacsd
+Keywords=Text;Editor;