[TxMt] assigning a scope to an empty line

[Domenico Carbotta]

1. ^\n matches an empty line (and by empty I mean EMPTY ;)
2. ^\s*?\n matches lines that are empty or contain only whitespace
3. ^\s*\n matches *groups of 1 or more consecutive lines* that are  
empty or contain only whitespace

I think (and experiments show that) $ before \n is superfluous.
(the difference btw. 2 and 3 is in the non-greedy "?" modifier, but  
I'm not good enough at regexes to explain you the Arcane Secrets :)

ciao,

Domenico