fix bug in scrapy parse command when spider is not specified explicitly. closes #209
add documentation topics: Broad Crawls & Common Practies
fixed doc typos
Remove firget imports
Possible set log-level in LogFormatter.dropped and LogFormatter.scraped
Merge pull request #213 from tonal/forget-import

Remove firget imports
Log level return from LogFormatter methods
Merge pull request #214 from tonal/log-level-dropped-item

Make LogFormatter return the log level (and require it)
Adds HtmlCSSSelector and XmlCSSSelector classes, cssselect as optional dependency.
Ported .get() from _Element and .text_content() from HTMLMixin
Add CSS selectors to scrapy shell
Documenting CSS Selectors (WIP)