Add support to set autoload for options

[mvdriel]

This is not supported by wp-cli: http://wp-cli.org/commands/option/

@tersmitten How do you want to realize this? By using wp-cli query?

[tersmitten]

@mvdriel Yes it is: http://wp-cli.org/commands/option/add/ :-)

[mvdriel]

@tersmitten It seems partly supported. Not on update http://wp-cli.org/commands/option/update/ I will implement this parameter for add tomorrow

[tersmitten]

https://github.com/wp-cli/wp-cli/issues/2081

[tersmitten]

Fixed in #35