Merge pull request #11 from victorng/master

Added maxID to getTimeline
Use STLog instead of NSLog. STLog defines to NSLog only when de DEBUG flag is set. Fixed issue #9 https://github.com/nst/STTwitter/issues/9
fixed signing error with non url-encoded get parameters (eg. search ‘new york’)
implemented POST lists/members/create
fixed POST lists/members/create methods signature
url-escape query string directly in getSearchTweetsWithQuery:successBlock:errorBlock:
don’t url-escape GET parameters
ensure signature is correct also for url-escaped GET parameters
moved STLog definition into STTwitterAppOnly.h
moved STLog definition into STTwitterAppOnly.h
Fixed getTimeline to match API call more closely. Added checks for null blocks within getTimeline