armadillo @5.20.2: update to 5.300.4

[Schamschula (Marius Schamschula)]

armadillo has been updated to version 5.300.4:

• added generalised Schur decomposition: qz()
• added .has_inf() and .has_nan()
• expanded interp1() to handle out-of-domain locations
• expanded sparse matrix class with .set_imag() and .set_real()
• expanded imag(), real() and conj() to handle sparse matrices
• expanded diagmat(), reshape() and resize() to handle sparse matrices
• faster sparse sum()
• faster row-wise sum(), mean(), min(), max()
• updated physical constants to NIST 2014 CODATA values
• fixes for handling sparse submatrix views
• Armadillo can make use of GPUs by linking with NVIDIA NVBLAS (a GPU-accelerated implementation of BLAS), or by linking with AMD ACML (which can use GPUs via OpenCL)

[Ionic (Mihai Moldovan)]

Thanks! Committed as r139163.