Timer threads consume too much CPU

[btbroot]

Estimation is ~0.05% per timer

[btbroot]

With a "standard" set of plugins and INI taken from the testing site, new ps: 0.2%. Below are various experiments results.

100 threads cap

1 blank plugin

ps: 0.2-0.3%

10 blank plugins

ps: 1.2-1.3% new: 0.5-0.8%

100 blank plugins

ps: 9.3-9.6% new: 1.8-2.4%

10 threads cap

100 blank plugins

ps: 9.1-9.2% new: 1.7-2.5%

1 thread cap

100 blank plugins

ps: 9.4-10% new: 1.7-1.9%

interval 200 ...............

ps: 4.4-6.7% new: 0.1-0.3%