add key_re options

[Dimonyga]

implement new functional

Example:
{"__fact_prefix::hbtest::string"=>"some test",
"hbtest::string::some_postfix"=>"test again"
}

options:
key_re: "__%{some_fact}_prefix::" //=> result: for hbtest::string = "some test"

options:
key_re: "::some_postfix" // => result: for hbtest::string = "test again"

Sorry for my bad english =(