allow line break at operators

[TheSaint]

Yingjie Lan wrote:

> #the new way
> x = 1+2+3+4+ #line continues as it is clearly unfinished
> 
> 1+2+3+4
> 
Genrally I prefer this way.
> Of course, the dot operator is also included, which may facilitate method
> chaining:
> 
> x = svg.append( 'circle' ).

Dot-ended is to tiny thing that might cause oversights. *If* it'll be used 
as a secondary option I think it doesn't matter, otherwise *if* use as a 
compulsory writing mode I'd say it is pretty mistake prone.