Remove __str__ and __repr__ from settings, introduce copy_to_dict() instead
Remove __str__ and __repr__ from settings, introduce copy_to_dict() instead

Settings instances as dict's are easier to print or pretty print in the shell

Fixes #1732

taito/scrapy,taito/scrapy,pablohoffman/scrapy,ssteo/scrapy,kmike/scrapy,barraponto/scrapy,darkrho/scrapy-scrapy,w495/scrapy,dracony/scrapy,rolando/scrapy,scrapy/scrapy,cyberplant/scrapy,Parlin-Galanodel/scrapy,carlosp420/scrapy,redapple/scrapy,dangra/scrapy,w495/scrapy,arush0311/scrapy,YeelerG/scrapy,crasker/scrapy,pawelmhm/scrapy,rolando-contrib/scrapy,carlosp420/scrapy,crasker/scrapy,pawelmhm/scrapy,umrashrf/scrapy,redapple/scrapy,shaform/scrapy,ArturGaspar/scrapy,crasker/scrapy,rolando-contrib/scrapy,rootAvish/scrapy,jc0n/scrapy,shaform/scrapy,starrify/scrapy,Ryezhang/scrapy,carlosp420/scrapy,dracony/scrapy,GregoryVigoTorres/scrapy,Ryezhang/scrapy,ArturGaspar/scrapy,GregoryVigoTorres/scrapy,YeelerG/scrapy,wujuguang/scrapy,ArturGaspar/scrapy,ssteo/scrapy,elacuesta/scrapy,wenyu1001/scrapy,rootAvish/scrapy,w495/scrapy,YeelerG/scrapy,foromer4/scrapy,eLRuLL/scrapy,shaform/scrapy,rolando-contrib/scrapy,umrashrf/scrapy,cyberplant/scrapy,arush0311/scrapy,eLRuLL/scrapy,Parlin-Galanodel/scrapy,kmike/scrapy,wujuguang/scrapy,elacuesta/scrapy,umrashrf/scrapy,wenyu1001/scrapy,rolando/scrapy,pablohoffman/scrapy,elacuesta/scrapy,starrify/scrapy,dangra/scrapy,rolando/scrapy,Parlin-Galanodel/scrapy,cyberplant/scrapy,wujuguang/scrapy,taito/scrapy,foromer4/scrapy,darkrho/scrapy-scrapy,Ryezhang/scrapy,pawelmhm/scrapy,jc0n/scrapy,starrify/scrapy,finfish/scrapy,scrapy/scrapy,jc0n/scrapy,dangra/scrapy,eLRuLL/scrapy,rootAvish/scrapy,GregoryVigoTorres/scrapy,finfish/scrapy,kmike/scrapy,wenyu1001/scrapy,barraponto/scrapy,redapple/scrapy,darkrho/scrapy-scrapy,barraponto/scrapy,arush0311/scrapy,ssteo/scrapy,finfish/scrapy,foromer4/scrapy,scrapy/scrapy,dracony/scrapy,pablohoffman/scrapy