Make "Blame NNNN" message translateable/configurable

[alexkrolick]

https://github.com/waderyan/vscode-gitblame/blob/master/src/controller.ts#L78

My coworkers are always ragging on me for "blaming" them in my editor, so it would be nice to be able to change the string to something less accusatory in the extension settings. It would also make it easy to translate.

[carloscz]

Hi, should be resolved by #26, you cannot change position of name / date parameters, but I think it is sufficient :)