Update shells/lshell to 0.19.6

Upstream changes:
-----------------

=== v0.9.16  14/08/2013 ===
    * Added support to login script. Thank you Laurent Debacker for the patch.
    * Fixed auto-complete failing with "-"
    * Fixed bug where forbidden commands still execute if strict=1
    * Fixed auto-completion complete of forbidden paths
    * Fixed wrong parsing &, | or ; characters
    * Added urandom function definition for python 2.3 compat
    * Corrected env variable expansion
    * Add support for cd command in aliases
    * Split lshellmodule in multiple files under the lshell directory
    * Fixed check_secure function to ignore quoted text
    * Fixed multiple spaces escaping forbidden filtering
    * Fixed log file permissions 644 -> 600
    * Added possibility to override config file option via command-line
    * Enabled job control when executing command
    * Code cleanup

=== v0.9.15.2 08/05/2012 ===
    * Corrected mismatch in aliaskey variable.

(gls)