Changed cookie handling: cookies are no longer shared between requests.
splash:set_user_agent
a tiny cleanup
a fix for copy-pasted exception message
headers argument for splash:go
splash:set_custom_headers
improve splash:go arguments validation
TST move splash:set_user_agent test to its own TestCase
splash:get_cookies()
splash:clear_cookies()
splash:clear_cookies() and splash:delete_cookies()
better decorator argument name
DOC move splash cookie methods docs below splash:har and splash:history
splash:add_cookie and splash:init_cookies
DOC markup fix
splash:url
Merge pull request #133 from scrapinghub/cookie-handling

Improved cookie and headers handling