v3.7.5

Enhancements

• Improve performance of applying remote changesets from sync.
• Improve performance of creating objects with string primary keys.
• Improve performance of large write transactions.
• Adjust file space allocation strategy to reduce fragmentation, producing
  smaller Realm files and typically better performance.
• Close network connections immediately when a sync session is destroyed.
• Report more information in InvalidDatabase exceptions.

Bugfixes

• Fix permission denied errors for RLMPlatform.h when building with CocoaPods
  and Xcode 10 beta 3.
• Fix a use-after-free when canceling a write transaction which could result in
  incorrect "before" values in KVO observations (typically nil when a non-nil
  value is expected).
• Fix several bugs in the merge algorithm that could lead to memory corruption
  and crashes with errors like "bad changeset" and "unreachable code".