[si] Port changes from si_tweaks to master
[compilers/default] -funroll-loops do more harm than good
Merge pull request #66 from Xarthisius/si_update

[streaming_global] update
[dot] use 64-bit huge values as limits of SFC indexes, not 32 ones
[dot] a comment on a way to extend maximum allowable effective resolution with SFC indexing
Merge pull request #67 from gawrysz/SFC_neighbors

Sfc neighbors