After meandering through the California drought, almond farming, and why his shower is better than yours, Bill Gross has decided to weigh in on bond liquidity. If you’ve read the financial press in the last month (quarter?) then most of his concerns will be familiar to you. Post-crisis regulation has forced banks to reduce their risk, but hasn’t really eliminated it; dealers aren’t as willing to lean against the market as they used to be; if the rather expensive bond market has a sell-off it could get ugly. But apparently it was recent news about PIMCO, the bond giant that…