v2.3.0

BEAST v2.3.0

Diff since v2.2.1

Merged pull requests:

• Add unitfunction for lagrange pyramid functions (#115) (@paresula)
• general linear mapping of bfs during reordering process in sauterschw… (#119) (@jayprakashdav)
• Higher order basis funs (#120) (@jayprakashdav)
• Add explicit static case (#121) (@djukic14)
• fixup: return correct scalartype for static operators (#124) (@sbadrian)
• Feature/enable mixed helmholtz discretizations (#125) (@sbadrian)
• Add Lippmann-Schwinger volume integral equation (HH3D VIE) (#126) (@bmergl)
• Add interpolation support for Helmholtz RHS (#127) (@sbadrian)
• Reactivate Runge Kutta Convolution Quadrature (#128) (@TimHRO)