The battle over a proposed Hatfield solar farm heats up with a lawsuit by a group of residents to stop it.  Citizens Energy Corp has proposed the solar array on 45 acres off Chestnut Street owned by the Szawlowski family.  The neighbors have hired lawyer Michael Pill to seek an injunction against the granting of a building permit for the project.  Pill says Citizens Energy can't just walz in and build without going through the public hearing process.  Northampton lawyer Patrick Melnick is representing the landowners.