Fix url_has_any_extension bug
reverted previous changed as it broke tests
added --pdb command option to enable pdb debugger on failure.
updated release notes with previous commit
Added check so that genspider cannot create a spider with the same name as the project.
doc: remove links to diveintopython.org, which is no longer available. closes #246
COMMANDS_MODULE setting allow : separated list of modules
added documentation
Merge branch 'master' of https://github.com/llonchj/scrapy
COMMANDS_MODULE accepts single module as string, multiple modules as colon separated string and tuple or list of modules.