NULL default-value fix
Now auto-serializes NSArray and NSDictionary field types
Added fetching by array of primary-key values, like "WHERE id IN (...)" in SQL
New podspec version
fix precision issue insert NSDecimalNumber

if insert NSDecimalNumber directly into sqlite, it will have precision
issue. so convert it into NSString first
Added convenient order-by lookup methods
Merge pull request #16 from allenwei/fix-insert-NSDecimalNumber

Fix NSDecimalNumber write precision