hush: typo fixes in comments

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
sed: open input files sequentially to avoid EMFILE

Currently, sed pre-opens all files, which may cause EMFILE errors
on systems with low ulimit -n.  Change sed to open one file at a time.

function                                             old     new   delta
get_next_line                                        177     235     +58
sed_main                                             682     652     -30
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/1 up/down: 58/-30)             Total: 28 bytes

Based on the patch by Daniel Borca <dborca@yahoo.com>

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
sed: code shrink

function                                             old     new   delta
get_next_line                                        246     250      +4
sed_main                                             671     662      -9
add_input_file                                        47       -     -47
------------------------------------------------------------------------------
(add/remove: 0/1 grow/shrink: 1/1 up/down: 4/-56)             Total: -52 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
dpkg-deb: cosmetic correction to usage text

Signed-off-by: Daniel Borca <dborca@yahoo.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
ping: try SOCK_DGRAM if no root privileges

Signed-off-by: Daniel Borca <dborca@yahoo.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>