Byte ordered index keys.

To improve speed of operations with indexes ignite can store keys in byte ordered format so only natural byte[] comparator will be enough to scan it.

Required features:

1) write any (almost) data types.

Must to have: boolean, byte, short, int,long, float, double, bigint, bigdecimal, String, Date, Time, DateTime.

Like to have: byte[], bitset

unlikely to have: timestamp with timezone

2) Support null values for any columns. Like to have: support nullFirst/nullLast

3) write asc/desc ordered (in any combination for columns, for indexes like "col1 asc, col2 desc, col3 asc").

Non functional requirements: space used and speed.