bitstream-io

An emergency update of dependencies doesn't qualify as
a semver update, apparently, but that additional SignedBitCount
method probably should. "cargo semver-check" has issues
with yanked crates, so it's difficult to check.

core2 hadn't been updated in years, so this is probably overdue.

Will do a new minor release just in case.

• Further extend VBR integer support

• Add io::Seek support to ByteReader

• Add support for LLVM-style variable bit rate integers

Update version to 4.6.0

• Add no alloc support

• Implement new CheckedSignedFixed type alias
• Implement FixedSignedBitCount for use by CheckedSignedFixed

• Implement new CheckedUnsignedFixed type alias
• Implement FixedBitCount for use by CheckedUnsignedFixed

• Add bytes method to ToByteStream traits with default implementations

• Add Checked API for avoiding redundant validation during writes
• Add BitCount-related helper methods to optimize unary writes

• Implement FromBitStreamUsing convenience trait
• Implement FromByteStreamUsing convenience trait
• Implement ToBitStreamUsing convenience trait
• Implement ToByteStreamUsing convenience trait

• Implement SignedBitCount for signed integer types.
• Remove endianness requirement for BitCounter
• Optimize BitRecorder implementation to be much faster
• Optimize read/write_bytes to be much faster for un-aligned bytes
• Seal Endianness traits from further downstream implementation

• Implement Integer for bool and arrays of Integer types.
• Add a read_const method to BitRead for consisency with BitWrite::write_const.
• Widen unknown BitCount values to handle more edge cases.

• Implement Integer for the unsigned NonZero types.
• Add byte alignment convenience methods.
• Fix BitCount.checked_sub for consistency with checked_add.