New syntax:
env export [-t | -b | -c] [-s size] addr [var ...]
With this change it is possible to provide a list of variables names
that shall be exported. Whenno arguments are given, the whole
environment gets exported.
NOTE: The new handling of the "size" argument means a change to the
user API.
Signed-off-by: Wolfgang Denk <wd@denx.de>