[BusyBox] yet more docs fixes

[Robert P. J. Day]

(loginutils directory)

passwd:

	-a option doesn't emphasize that it takes a value in docs

sulogin:

	perhaps i'm misreading something, but the docs list the same 
	options for sulogin as for su, and yet the source for sulogin.c
	refers to at least a "-t" option, and none of those listed in
	the documentation.


(miscutils directory)

crond:

	online docs are a bit messed up, synopsis of command is missing
 	a couple options.

makedevs:

	TYPEs include:


        b:      Make a block (buffered) device.
        c or u: Make a character (un-buffered) device.
        p:      Make a named pipe. MAJOR and MINOR are ignored for  ...

  source code does not appear to recognize type "u".

strings:
	strings [-afo] [-n length] [file ... ] 

	Display printable strings in a binary file.

        -f      Precede each string ...
        -n N    Specifies that at least N characters ...
        -o      Each string is preceded by its decimal offset in the file.

  list does not mention "-a" option in synopsis

time:

	docs don't mention "-p" option for POSIX format


rday