Makefile: remove tests from "make all"

Instead, introduce "make reallyall" and make it the default target. Now,
one can override the default target using localconf.

Needed for preparing Gentoo ebuild test behavior.

Signed-off-by: Kai Krakow <kai@kaishome.de>

Makefile

@@ -10,7 +10,12 @@ MARKDOWN := $(firstword $(shell which markdown markdown2 markdown_py 2>/dev/null
 # allow local configuration to override above variables
 -include localconf
 
-default all: lib src scripts test README.html
+DEFAULT_MAKE_TARGET ?= reallyall
+
+default: $(DEFAULT_MAKE_TARGET)
+
+all: lib src scripts README.html
+reallyall: all test
 
 clean: ## Cleanup
 	git clean -dfx -e localconf