Remove Shape#[] and Shape#[]=
move method : from Worksheet#position_shape_emus to Shape#calc_position_emus
Drawing#write_nv_cxn_sp_pr : to be simple
shape.rb : remove unused comment lines.
add Shape#set_position
Worksheet#insert_shape : to be simple
Worksheet#insert_shape : remove shape.palette setting, because already set in Worksheet#add_shape
Worksheet#insert_shape : to be simple
move method : from Worksheet#auto_locate_connectors to Shape#auto_locate_connectors
move method : Worksheet#validate_shape to Shape#validate
add Shape#dimensions