Currently with default simplenode template, `appname console other_args`
will pass ["console", "other_args"] as plain arguments. But
`appname start other_args` effectively calls `appname console`. This
patch replaces this call with `appname console other_args`.

`init:get_plain_arguments()` returns `["console", "more_args"]` when
started with `$APP_NAME console more_args`, but `["console"]` when
started with `$APP_NAME start more_args`. This patch makes `start`
behave like `console` in this respect.

The trailing slash for PIPE_DIR is necessary for
both start and attach operations.

To support OTP release upgrades I have added support for building
upgrade packages. Support for this is included in the
rebar_upgrade module, specifically generate_upgrade/2. It requires
one variable to be set on the command line 'previous_release' which
is the absolute path or relative path from 'rel/' to the previous
release one is upgrading from. Running an upgrade will create the
needed files, including a relup and result in a tarball containing
the upgrade being written to 'rel/'. When done it cleans up the
temporary files systools created.

Usage:
$ rebar generate-upgrade previous_release=/path/to/old/version

This also includes a dummy application that can be used to test
upgrades as well as an example.

Special thanks to Daniel Reverri, Jesper Louis Andersen and
Richard Jones for comments and patches.

missing from the PIPE_DIR definition above, the application won't start and
doesn't log any thing to the expected locations.