huge 1.5

• BLAS acceleration for graphical lasso and TIGER solvers (2-3x speedup at d >= 200).
• Added strong screening rule for graphical lasso.
• Removed RcppEigen dependency; the package now uses lightweight C++ headers with direct BLAS calls.
• Added testthat test suite.
• Added TIGER to DESCRIPTION text.
• Fixed Makevars.win BLAS linking.
• Fixed nonparanormal transform (huge.npn) rownames bug.
• Fixed documentation typos and parameter reference errors.