v2.2.3

Backport various improvements from the 2.3 series:

 - install 1/2/3 mismatch score tables
 - use installed 7mer-3mismatch table by default
 - use installed 3mer (Yan et al.) or 4mer (Wee et al.) by default
 - check for sparse solver availability at runtime
 - fix parsing of gene names from NCBI FASTA
 - remove SuperLU MT codepath that was not intended for 2.2 series
 - add support for OpenBLAS and ATLAS flavours of CBLAS
 - factor kother contribution into Km
 - fix bug in target site vacancy formula