nolisten=1 no longer works in bitcoin.conf #846

From the forum annoucement:

The -nolisten, -noupnp and -nodnsseed command-line options were renamed to -listen, -upnp and -dnsseed, with a default value of 1. The old names are still supported for compatibility

but that's only true on the command line, not for bitcoin.conf options.

I have a bitcoin.conf with "nolisten=1" in it, but it's being ignored.

The "interpret -nofoo as -foo=0 (and -nofoo=0 as -foo=1, as long as -foo not set)" code is in util.cpp's ParseParameters() function and runs before the bitcoin.conf file is even read.

This breaks existing configuration files, so it's probably best to fix this before the release of 0.6.

I should probably draw attention to the change I made to the comment too. I think the closing paren was in the wrong place before:

•    //  interpret -nofoo as -foo=0 (and -nofoo=0 as -foo=1, as long as -foo not set)

•    // interpret -nofoo as -foo=0 (and -nofoo=0 as -foo=1) as long as -foo not set

Fixed in #852.