Remove the "project" feature

Remove the "project" feature

The "project" feature was designed to allow to several projects to be
built inside the same Buildroot source tree and allowing the toolchain
and non-configurable packages to be shared between the different
projects on the same architecture. While being interesting in theory,
this feature adds a level of complexity to Buildroot, both from an
user perspective and from a developer perspective, while one of the
main Buildroot strengh is to be simple. Moreover, this feature is only
seldomly used by our users.

From a user-level perspective, this for example allows to remove the
project_build_ARCH directory, which was very confusing. The
autotools-stamps directory is also removed, since these stamps are
back at their normal location.

Description of the changes involved :

 * project/, directory removed

 * Makefile

    - Don't include project/Makefile.in and project/project.mk anymore

    - Grab a copy of the contents of project/Makefile.in at the
      location it was imported, but remove the definition related to
      PROJECT_BUILD_DIR. The TARGET_DIR is now in
      $(BUILD_DIR)/target_dir

    - Remove the creation/removal of the $(PROJECT_BUILD_DIR) and
      $(PROJECT_BUILD_DIR)/autotools-stamps directories

    - Don't make world depends on target-host-info. This target was
      defined by project/project.mk to customize /etc/issue,
      /etc/hostname and create /etc/br-version depending on the
      project definitions. We can of course imagine re-adding such a
      feature later.

    - Replace PROJECT_BUILD_DIR by BUILD_DIR everywhere

    - Remove the update, log and lognr.$(PROJECT) target, they were
      specific to the project feature.

 * package/Makefile.autotools.in

    - Replace PROJECT_BUILD_DIR by BUILD_DIR for the location of the
      configure cache

    - Move the INSTALL_TARGET and HOOK_POST_INSTALL stamps to the same
      directory as the other stamps (i.e, in the package directory).

 * package/Makefile.in

    - Replace PROJECT_BUILD_DIR by BUILD_DIR for the location of the
      configure cache

 * package/at/at.mk,
   package/busybox/busybox.mk,
   package/busybox/initramfs.mk,
   package/customize/customize.mk,
   package/linux-fusion/linux-fusion.mk,
   package/ltp-testsuite/ltp-testsuite.mk,
   package/nfs-utils/nfs-utils.mk,
   target/cpio/cpioroot.mk,
   target/cramfs/cramfs.mk,
   target/device/Atmel/DataFlashBoot/DataflashBoot.mk,
   target/device/Atmel/Makefile.in,
   target/device/Atmel/at91bootstrap/at91bootstrap.mk,
   target/device/KwikByte/Makefile.in,
   target/ext2/ext2root.mk,
   target/initramfs/initramfs.mk,
   target/iso9660/iso9660.mk,
   target/jffs2/jffs2root.mk,
   target/linux/Makefile.in,
   target/romfs/romfs.mk,
   target/squashfs/squashfsroot.mk,
   target/tar/tarroot.mk,
   target/ubifs/ubifsroot.mk

    - Replace PROJECT_BUILD_DIR by BUILD_DIR

 * target/device/Config.in

    - Do not include project/Config.in anymore

 * target/linux/Makefile.in.advanced

    - Replace PROJECT_BUILD_DIR by BUILD_DIR

    - Store the stamps file in $(STAMP_DIR) instead of
      $(PROJECT_BUILD_DIR)/autotools-stamps

 * target/u-boot/Makefile.in

    - Replace PROJECT_BUILD_DIR by BUILD_DIR

    - Remove $(PROJECT) from the U-Boot target binary name

    - Remove the insertion in the configuration of the project name as
      the hostname

    - The u-boot-autoscript target now generates
      $(U_BOOT_AUTOSCRIPT).img instead of
      $(U_BOOT_AUTOSCRIPT).$(PROJECT)

 * toolchain/gcc/gcc-uclibc-3.x.mk
   toolchain/gcc/gcc-uclibc-4.x.mk

    - Move the stamps files to $(STAMP_DIR)

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>