scs 3.3.1

Synced up to version 3.3.1 of the SCS C library. The package version now matches the library version.
New cones: complex positive semidefinite (cs). Box cone bsize defaults to length(bl) + 1.
New info fields from 3.3.1, including aa_stats; new scs_version().
Anderson acceleration is now on by default, as in SCS: acceleration_lookback = 10L, acceleration_interval = 5L (were 0L and 1L). Pass the old values to restore the previous behavior.
Unknown control names now give a warning (they were silently ignored); unknown cone fields are an error.
A negative acceleration_lookback is now an error; use acceleration_type_1 = FALSE for type-II Anderson acceleration.
A and P accept base matrices, dgCMatrix (and dsCMatrix for P) and simple_triplet_matrix; other Matrix classes give an error.
Test suite regenerated from the upstream C tests (83 reference problems, checked with upstream’s assertions).
Upstream modifications are documented in src/scs_mods/README.md.

scs 3.0-0

Set acceleration_lookback parameter to (current default) 10L from previous value of 20L.
Fixed up flags for compiling with Oracle Developer Studio compilers.
Edited and cleaned up test_socp which had copy of test_psd repeated.