Tracking issue for tasks related to unary "universal functions," elementwise functions of a single tensor input.

Tasks

• Alias rad2deg and degrees
• Alias deg2rad and radians
• torch.real and np.real are divergent on non-complex dtypes
• torch.imag and np.imag are divergent on non-complex dtypes
• Alias conj and conjugate
• Alias bitwise_not and invert
• Add integral type support to ceil, floor, round, and trunc
• Alias mvlgamma and multigammaln

cc @ezyang @gchanan @zou3519 @bdhirsh @jbschlosser @anjali411 @mruberry @rgommers @heitorschueroff