Use current text selection when looking up a definition

[zeflash]

Right now, hitting shift+cmd+R opens the global definition list, but it's empty. If it used the current selected text it'd be much easier to navigate around

[coder79]

Second this.

I would also ask that goto_definition consider the selected text. Our code base generates smart pointers so we use a lot of FooRef which would be nice if it would jump to Foo. Or possibly goto_definition could accept the symbol as a parameter and I'll strip the 'Ref' before passing in the symbol.