Added mask to File cache docblock
Merge pull request #1566 from andraskende/master

Update file cache docs to include the mask setting.

Refs #1566
Correctly generate bigint primary keys in sqlite.

generate bigint primary keys correctly. Autoincrement cannot be set as
it only works with INTEGER columns[1]. I decided to use some string
manipulations as the entire SQL generation bits are a bit janky and I've
already re-written them for 3.0.

[1] https://www.sqlite.org/autoinc.html

Closes #GH-1552