[ANN] autoproj updated !

Short changelog
---------------

acd <package> cd's you to the source directory for <package>.
Shortcuts "a la" zsh can be used:
acd o/types
will match base/orogen/types if it is unambiguous.

amake is a shortcut for "autoproj build"

-k now works for package updates as well. autoproj still obviously
has to fail on checkout (i.e. if a required packages is not present
yet)

autobuild now supports importer fallbacks. This can be used to switch
to local mirrors in case the main server is down.
See
http://gitorious.com/rock/buildconf-all/blobs/master/gitorious.rb for an
example

The Package#remove_obsolete_installed_file(*path) helper method
allows to remove obsolete files from the installation prefix. This is
useful to ensure smooth upgrades when some files get moved between
different packages.

Complete changelog
------------------
= Autoproj v1.7.3
== For basic usage
* amake is a command that is a shortcut to "autoproj
build". I.e. amake . will build the package in the
current directory and all its dependencies
* added tag support. The manifest and the autobuild
files allow to add textual tags to packages, that
will be picked up by documentation later on.
Moreover, some tags can be used to tune the build.
For instance, rock uses the 'stable' tag to set the
CMAKE_BUILD_TYPE variable on cmake packages to
either Debug (non-stable) or RelWithDebInfo
(stable).

== For advanced usage
* support ignoring/excluding OS packages
* define Package#post_import which allows to run a
code block after the package has been imported, but
before the build. The global
Autoproj.post_import do |pkg|
end
allows to do it for all defined packages.
* define Package#remove_obsolete_installed_file(*path)
which allows to remove files from the installation
directory. Useful for simple upgrade cases, when
files move from one package to another
* in source.yml, a package name is interpreted as a
regular expression only if it contains
non-alphanumeric characters. This avoids some
surprising effects if the name of package BlaBla is
a subset of the package BlaBlaBlo

== Autobuild v1.5.31
* allow to override the type export policy for oroGen
>= 1.1
* allow to provide CMAKE_MODULE_PATH in the cmake
handler. Unfortunately, cmake does not support
setting this through environment variables, so we
have to pass it as a variable definition using the -D
command line parameter
* make ignore_errors work for updates as well. We
obviously still have to fail on checkout