[Toybox] Fixes to mkdir, chown, env

[Jacek Bukarewicz]

>
> $ touch walrus
> $ sudo chown root.bin walrus
> $ ls -l walrus
> -rw-rw-r-- 1 root bin 0 Sep  5 05:16 walrus
>
> It's not posix but busybox supports it too and it's used in the 
> ./configure stage of various package builds. (Do you have a specific 
> reason to remove it?)
>
Indeed, busybox and GNU coreutils also allow dot as delimiter (probably 
for historical reasons)
I encountered this issue while testing commands that we use in our 
environment and which could possibly be replaced by toybox. I tried to 
chown a file to my user so I typed ./toybox chown j.bukarewicz xxx and 
toybox complained about nonexisting user 'j'. Busybox also fails, GNU 
coreutils works as expected. I wasn't aware at that point that dot is 
allowed as delimiter, especially when manual or --help only say about colon.
It's nothing big. If we ever need another behavior we can probably 
maintain patches locally.

Thanks,
Jacek

 1378378959.0