* Install the standalone (scons-local) version

  Advantages:
  - The regular version of SCons requires distutils during installation;
    the standalone version does not have this requirement

  Disadvantages:
  - The scons-local package is not available from the Fossies mirror
  - The patch will need to be manually updated with each version update

* Install files to $(STAGING_DIR_HOSTPKG) instead of $(STAGING_DIR_HOST)

* Write the correct shebang into scripts instead of using the wrapper

* Update to 3.1.2

Signed-off-by: Jeffery To <jeffery.to@gmail.com>

This patch aims to move scons host build tool into packages feeds, where
this tools belongs. There are currently no packages in the master tree
which would need scons, yet scons is build always as part of host tools,
just in order to satisfy host build dependency of few packages in the
packages feeeds.

Signed-off-by: Petr Štetiar <ynezz@true.cz>