gitweb/Makefile: add a $(GITWEB_ALL) variable

Declare the targets that the "all" target depends on with a new
$(GITWEB_ALL) variable. This will help to reduce churn in subsequent
commits.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

gitweb/Makefile

@@ -54,6 +54,11 @@ ifneq ($(MAKECMDGOALS),clean)
 -include ../GIT-VERSION-FILE
 endif
 
+# What targets we'll add to 'all' for "make gitweb"
+GITWEB_ALL =
+GITWEB_ALL += gitweb.cgi
+GITWEB_ALL += static/gitweb.js
+
 ### Build rules
 
 SHELL_PATH ?= $(SHELL)
@@ -92,7 +97,7 @@ ifndef V
 endif
 endif
 
-all:: gitweb.cgi static/gitweb.js
+all:: $(GITWEB_ALL)
 
 GITWEB_PROGRAMS = gitweb.cgi