* Add uint16 subkeys back - in the fixes above the hashing impact was muted.

* Uint16 subkeys give 40% memory savings in the main case of 16 bytes KVP and only cause a single-digit drop in speed for TimePeriod key. Could create an option 'optimize.speed/memory' if one have to load a lot of data in memory.

TODO
* Start reworking old Series, Spreads and Windows
* Bucket DU and load/save inner maps

MEDIUM
* TimePeriod correctness tests
* SHM inner maps to syncronized and outer map lock only when outer is being modified

LOW
* TimePeriod direct parsing from string

# SHM with uint16 vs. 'K subkeys
========================
Less memory	-39%
					uint16		'K		Less speed
SHM Time Period Add, #1000000, ops	3,267,973	3,300,330	-1.0%
SHM Time Period Add, #1000000, ops	3,636,363	3,846,153	-5.5%
SHM Time Period Add, #1000000, ops	3,412,969	3,717,472	-8.2%
SHM Time Period Add, #1000000, ops	3,558,718	3,412,969	4.3%
SHM Time Period Add, #1000000, ops	3,048,780	3,875,968	-21.3%
					3,384,961	3,630,578	-6.8%

SHM Time Period Iterate, #1000000, ops	11,363,636	10,869,565	4.5%
SHM Time Period Iterate, #1000000, ops	14,285,714	14,705,882	-2.9%
SHM Time Period Iterate, #1000000, ops	17,241,379	18,518,518	-6.9%
SHM Time Period Iterate, #1000000, ops	15,151,515	15,625,000	-3.0%
SHM Time Period Iterate, #1000000, ops	14,492,753	15,151,515	-4.3%
					14,506,999	14,974,096	-3.1%

SHM Time Period Read, #1000000, ops	2,262,443	2,597,402	-12.9%
SHM Time Period Read, #1000000, ops	2,457,002	2,610,966	-5.9%
SHM Time Period Read, #1000000, ops	2,583,979	2,857,142	-9.6%
SHM Time Period Read, #1000000, ops	2,531,645	2,666,666	-5.1%
SHM Time Period Read, #1000000, ops	2,688,172	2,617,801	2.7%
----------------				2,504,648	2,669,995	-6.2%

# SHM with uint16 subkeys
========================
Test Name:	SHM_run
Test Outcome:	Passed
Result StandardOutput:
SHM<1024> Add, #1000000, ops: 5464480, mem/item: 10
SHM Read, #1000000, ops: 3690036, mem/item: 0
SHM Iterate, #1000000, ops: 9433962, mem/item: 0
SHM<1024> Add Reverse, #100000, ops: 1587301, mem/item: 10
SHM Read Reverse, #100000, ops: 4347826, mem/item: -10
SHM Time Period Add, #1000000, ops: 3267973, mem/item: 11
SHM Time Period Read, #1000000, ops: 2262443, mem/item: 0
SHM Time Period Iterate, #1000000, ops: 11363636, mem/item: -11
SHM Time Period Add, #1000000, ops: 3636363, mem/item: 11
SHM Time Period Read, #1000000, ops: 2457002, mem/item: 0
SHM Time Period Iterate, #1000000, ops: 14285714, mem/item: -11
SHM Time Period Add, #1000000, ops: 3412969, mem/item: 11
SHM Time Period Read, #1000000, ops: 2583979, mem/item: 0
SHM Time Period Iterate, #1000000, ops: 17241379, mem/item: -11
SHM Time Period Add, #1000000, ops: 3558718, mem/item: 11
SHM Time Period Read, #1000000, ops: 2531645, mem/item: 0
SHM Time Period Iterate, #1000000, ops: 15151515, mem/item: -11
SHM Time Period Add, #1000000, ops: 3048780, mem/item: 11
SHM Time Period Read, #1000000, ops: 2688172, mem/item: 0
SHM Time Period Iterate, #1000000, ops: 14492753, mem/item: -11
----------------

# SHM with 'K subkey
========================
Test Name:	SHM_run
Test Outcome:	Passed
Result StandardOutput:
SHM<1024> Add, #1000000, ops: 6896551, mem/item: 16
SHM Read, #1000000, ops: 4524886, mem/item: 0
SHM Iterate, #1000000, ops: 10752688, mem/item: 0
SHM<1024> Add Reverse, #100000, ops: 1149425, mem/item: 16
SHM Read Reverse, #100000, ops: 4545454, mem/item: -16
SHM Time Period Add, #1000000, ops: 3300330, mem/item: 18
SHM Time Period Read, #1000000, ops: 2597402, mem/item: 0
SHM Time Period Iterate, #1000000, ops: 10869565, mem/item: -18
SHM Time Period Add, #1000000, ops: 3846153, mem/item: 18
SHM Time Period Read, #1000000, ops: 2610966, mem/item: 0
SHM Time Period Iterate, #1000000, ops: 14705882, mem/item: -18
SHM Time Period Add, #1000000, ops: 3717472, mem/item: 18
SHM Time Period Read, #1000000, ops: 2857142, mem/item: 0
SHM Time Period Iterate, #1000000, ops: 18518518, mem/item: -18
SHM Time Period Add, #1000000, ops: 3412969, mem/item: 18
SHM Time Period Read, #1000000, ops: 2666666, mem/item: 0
SHM Time Period Iterate, #1000000, ops: 15625000, mem/item: -18
SHM Time Period Add, #1000000, ops: 3875968, mem/item: 18
SHM Time Period Read, #1000000, ops: 2617801, mem/item: 0
SHM Time Period Iterate, #1000000, ops: 15151515, mem/item: -18
----------------