Update doc history, regenerate.

[SVN r84297]
Fix typos.

[SVN r84535]
Fix assignment operations to be safe after a move.
Added test cases to catch bug case.
Refs #8667.

[SVN r84687]
Fix for 0 % N giving wrong answer in cpp_int.
Refs #8670.

[SVN r84716]
Change type of string index to std::string::difference_type.

[SVN r84729]
Apply patch from #8692.
Refs #8692.

[SVN r84763]
Add some noexcept specs to gmp_int.

[SVN r84777]
Fix bug in shift operator that doesn't always normalise when we should.

[SVN r84795]
Update change history, regenerate docs.

[SVN r84797]
Make unary + operator return by value - we can generate dangling references otherwise.

[SVN r84863]
Fix MPFI constant initialization.

[SVN r84866]
Add some typecasts to ensure conversion from negative values proceeds correctly.
Fix masking of values during construction so overflow wraps around in unchecked fixed precision integers.
Add tests for above changes.
Refs #8711.

[SVN r84897]
Add missing #include

[SVN r84898]
Remove some unused typedefs: fixes some gcc-4.8 warnings

[SVN r84904]
Apply remaining fixes from #8732.
Also adds msb (most significant bit) function to multiprecision.
Fixes #8732.

[SVN r84921]
Change to use std::string::size_type rather than unsigned.
Fixes #8748.

[SVN r84922]
Fix left shift operator.
Fixes #8741.

[SVN r84925]
Correct output of small-integer types.
Fixes #8745.

[SVN r84928]
Update history and regenerate docs.

[SVN r84939]
Reorganise bit scanning code.
Add tests for msb function.

[SVN r84972]