Fix decorators to allow the same kind of characters that functions do

syntax/python.vim

 "
 
 syn match   pythonDecorator	"@" display nextgroup=pythonDottedName skipwhite
-syn match   pythonDottedName "[a-zA-Z_][a-zA-Z0-9_]*\%(\.[a-zA-Z_][a-zA-Z0-9_]*\)*" display contained
+syn match   pythonDottedName "\%([^[:cntrl:][:space:][:punct:][:digit:]]\|_\)\%([^[:cntrl:][:punct:][:space:]]\|_\)*\%(\.\%([^[:cntrl:][:space:][:punct:][:digit:]]\|_\)\%([^[:cntrl:][:punct:][:space:]]\|_\)*\)*" display contained
 syn match   pythonDot        "\." display containedin=pythonDottedName
 
 "

test.py

 
 @ decoratorname
 @ object.__init__(arg1, arg2)
+@ декоратор.décorateur
 
 # Numbers