Backport critical fixes from develop#1828

Merged

UdjinM6 merged 9 commits intodashpay:v0.12.2.xfrom

UdjinM6:bp_1810_1819

Jan 10, 2018

Commits on Jan 5, 2018

Fix crash on exit when -createwalletbackups=0 (#1810)

codablock
authored and
UdjinM6
committed
Swap iterations and fUseInstantSend parameters in ApproximateBestSubset (#1819)

codablock
authored and
UdjinM6
committed
Merge #8256: BUG: bitcoin-qt crash

laanwj
authored and
UdjinM6
committed

Commits on Jan 6, 2018

Commits on Jan 9, 2018