terminal: Run command using a wrapper script

terminal: Run command using a wrapper script

Some terminals may not pass the environment into the child process. This
is true when using "tmux split-window." If tmux is already running, it
will start the command with the tmux session environment, ignoring the
environment where the command was issued.

This could possibly be worked around when launching tmux by injecting
variables into the user's session environment or adding the variables to
the "update-environment" tmux setting. However, both methods would
permanently alter the user's session, which is undesirable.

By using a wrapper script, we have full control over the final
environment. Replace the env dictionary with an empty data smart that
will contain the exported variables and a wrapper function that execs
the original command.

(From OE-Core rev: 3bb96671e987ce8110ce98b9f6d9efc093f8d20e)

Signed-off-by: Tyler Hall <tylerwhall@gmail.com>
Signed-off-by: Saul Wold <sgw@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>