Merge web/blob/Makefile into web/Makefile

While the recent commit 7e5745f solved the issue of having an
independent blob-stamp file, which was possible to become out of
sync with the necessary web/blob/files.go file, this change further
simplifies the setup by merging the two Makefile.
The only purpose of web/Makefile was to call targets in
web/blob/Makefile. As all dependencies for blob/files.go are
outside of the blob/ directory, the separation isn't logically
necessary.

web/Makefile

@@ -11,12 +11,17 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-all: blob
+include ../Makefile.INCLUDE
 
-blob:
-	$(MAKE) -C blob
+all: blob/files.go
+
+SUFFIXES:
+
+# Do not embed map files and the non-minified bootstrap files.
+blob/files.go: $(shell find templates/ static/ -type f)
+	../utility/embed-static.sh static templates | $(GOFMT) > $@
 
 clean:
-	$(MAKE) -C blob clean
+	-rm -f blob/files.go
 
-.PHONY: clean blob
+.PHONY: clean

web/blob/Makefile

@@ -1,27 +0,0 @@
-# Copyright 2013 The Prometheus Authors
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-# http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-
-include ../../Makefile.INCLUDE
-
-all: files.go
-
-SUFFIXES:
-
-# Do not embed map files and the non-minified bootstrap files.
-files.go: $(shell find ../templates/ ../static/ -type f)
-	../../utility/embed-static.sh ../static ../templates | $(GOFMT) > $@
-
-clean:
-	-rm  files.go
-
-.PHONY: clean