It’s like a boy taking the training wheels off for the first time. Or a young lady going on her first date. Or a senior heading off to college. So far as we can tell, this is Twitter’s coming of age party. Yep — after receiving a very generous $250 million valuation late last month, the microblogging phenomenon has locked down even more capital.In a recent post to the Twitter, Inc. blog, the company proclaimed that it had increased active users by 900 percent in just a year, and while its web traffic is astounding,