Default permalinks suck

[aaemnnosttv]

The new command should do one of the following:

• Set permalinks to use the most common /%postname%/ by default
• Accept a --pretty-permalinks flag to set permalinks to /%postname%/
• Accept a --permalinks=<structure> flag to allow a specific permalink structure to be set

Perhaps --pretty-permalinks is just a shortcut for --permalinks=/%postname%/.