Minor improvements to the "Private testnet howto" documentation

[RuneStone0]

1) Missing = sign between input parameter and value
After following the documentation (http://docs.bitshares.org/testnet/private-testnet.html), I noticed several bugs. This was tested on Ubuntu. When running the following command:

witness_node --data-dir data

The "data" parameter is ignored and the default "witness_node_data_dir" was used instead, causing some confusion. To solve this add an equal sign:

witness_node --data-dir=data

I suggest the documentation is updated to be more consistent, so all input parameter/values are illustrated using param=value.

2) Confusing config.ini configuration and cli_wallet end-point used
I suggest the following changes to config.ini (use port 8090 instead of 11011):

rpc-endpoint = 127.0.0.1:8090
genesis-json = my-genesis.json
enable-stale-production = true

To me it was a bit confusing that the suggested rpc-endpoint port number was 11011 (which is the default port for the p2p network). To avoid this confusion, lets use :8090 instead? This will make it more aligned when the rest of the documentation, when cli_wallet connects to a witness end-point.

[abitmore]

1. Missing = sign between input parameter and value

This is due to a bug of a boost 1.60. If you compile with boost 1.58, the = sign can be omitted.

rpc-endpoint port number was 11011

Contributions are appreciated. Best if you can submit a pull request.

[abitmore]

Please submit PR against the docs repository. The source file is here. Closing this one.

[abitmore]

Forwarded here: bitshares/docs.bitshares.org#51

[cedar-book]

done