Merge pull request #120 from idosavion/ido/fix-crash-on-windows

ido/fix crash on windows

Ensure expired items do not load

See #112

Use absolute expiration in peristed db file

This commit ensures that the absolute unix expiration timestamp
is stored for applicable records in the persisted db file.

Previously the relative seconds was stored.

fixes #85

Updated dependencies

Upgrade btree dependency

Upgrade gjson and btree

Upgrade modules

Estimate last oof size on open

addresses #77

Use btree with non-concurrent mode

Minor optimization

Updated dependencies