ash: factor out ASH_HELP config option

It used to be aliased to !FEATURE_SH_EXTRA_QUIET for ash,
while hush had it separate from FEATURE_SH_EXTRA_QUIET.

Bring ash in line with hush.

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
ash: fix off-by-one in "jobs %4" handling. closes 7310

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
mdev: treat zero-length /dev/mdev.seq the same as "\n" one. Closes 7334

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
vi: fix incorrect memory access on brace matching. Closes 7256

While at it, fix brace matching to actually show the match
(missed fflush was causing cursor positioning to be buffered);
shorten brace matching code; remove unused macro indirection
in indicate_error().

Custom linker script 'busybox_ldscript' found, using it
function                                             old     new   delta
indicate_error                                         -      61     +61
mysleep                                               43      56     +13
char_insert                                          483     486      +3
find_pair                                            167     124     -43
Indicate_Error                                        61       -     -61
------------------------------------------------------------------------------
(add/remove: 1/1 grow/shrink: 2/1 up/down: 77/-104)           Total: -27 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
ftpd: make LIST command show dotfiles too

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
sed: fix a buglet in s///NUM handling

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
sherpya: android port
added my default config