Improve consistency in the C++ interface

[cubicYYY]

These changes aim to improve the consistency of the C++ API between the 32-bit version and the 64-bit version.

Related issues: #629

Changes:

• Rename RoaringSetBitForwardIterator to RoaringSetBitBiDirectionalIterator (the old one is now deprecated).
• Add methods: Roaring::clear Roaring::isFull Roaring::containsRangeClosed.
• Revise move_equalorlarger methods in iterators.
• Add the api::roaring_bitmap_flip_inplace_closed method.
• Add the api::roaring_bitmap_contains_range_closed method.
• Add the api::roaring_bitmap_flip_closed method.
• Add the api::roaring_bitmap_range_cardinality_closed method.
• Other minor changes.

If merged, only the following methods remain that are only implemented in the 32-bit version(in class Roaring) but not in the 64-bit version(in class Roaring64Map):

• [ ] containsRange
• [ ] rangeUint64Array
• [ ] and_cardinality
• [ ] or_cardinality
• [ ] andnot_cardinality
• [ ] xor_cardinality
• [ ] jaccard_index
• [ ] rank_many

Also, the methods mentioned in #549 need to be further implemented.

[lemire]

Looks good to me. I invited others to comment.

Let us keep the breaking changes to a minimum. Deprecation is fine.

[lemire]

Running tests with the latest changes.

[lemire]

Merging.