shell: make it possible to alias one of shells to "bash"

function                                             old     new   delta
packed_usage                                       27047   27054      +7
applet_names                                        2227    2232      +5
applet_main                                         1304    1308      +4
applet_nameofs                                       652     654      +2
applet_install_loc                                   163     164      +1
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 5/0 up/down: 19/0)               Total: 19 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
3 files changed