v1.5.5

Got another bug report, but then found heaps more issues while fixing.

• Fixed nil table entries between other values disappearing when decoding by writing them late
• Fixed false dictionary keys not being created by the decoder due to a faulty if case
• Fixed tables with only nil and boolean entries being falsely flagged as compatible for Boolean5 compression
• Fixed tables with nil entries being falsely detected as a dictionary
• Removed leftover debugging print for Boolean5 compression being triggered

Full Changelog: v1.5.4...v1.5.5