Add build-indep and build-arch targets as aliases for build

The current build target is responsible for the generation of
architecture dependent and independent files. The architecture
independent files are just sed'ed and as such they take insignificant
build time, so splitting that from the general build process does not
seem worth the trouble or complexity. Renaming the current build
target to build-arch though would be incorrect.

debian/changelog

@@ -158,6 +158,8 @@ dpkg (1.16.1) UNRELEASED; urgency=low
   * Refer to Sources and Packages files as part of a repository instead of
     as being of exclusive use or owned by APT, which has never been the case.
   * Unify somewhat dpkg-maintscript-helper --help output with other commands.
+  * Add build-indep and build-arch targets as aliases for build in
+    debian/rules.
   * Fix possible segfault of dpkg in findbreakcycle(). LP: #733414
 
   [ Bill Allombert]

debian/rules

@@ -58,7 +58,7 @@ build-tree/config.status: configure
 		--with-bz2
 
 # Build the package in build-tree
-build: build-tree/config.status
+build-indep build-arch build: build-tree/config.status
 	dh_testdir
 
 	cd build-tree && $(MAKE)