0.2.0.0

• Remove hand-written 'Num', 'Real', 'Integral', 'Bits' instances.
• Derive 'Bits' and 'FiniteBits' instances.
• Expose 'Bit' constructor directly and remove 'fromBool' function.
• Rename 'toBool' to 'unBit'.

0.1.1.0

• Fix bugs in MVector and Vector instances of Bit.
• Speed up MVector and Vector instances of Bit.