Key TakeawaysDollar General reported second-quarter earnings below analysts' estimates and lowered its projections for the full year.CEO Todd Vasos said Dollar General is seeing a "core customer who feels financially constrained."Shares of Dollar General plunged in early trading Thursday following the news. Dollar General (DG) shares tumbled Thursday morning after the discount retailer reported weaker-than-expected earnings for the second quarter lowered its projections for full-year revenue. Dollar Genera ...