Update integrated dtoa.c with improved multi-threaded performance#55

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exjesper wants to merge 5 commits intoopenresty:masterfrom

exjesper:updated-dtoa

Commits on Jan 22, 2020

Add updated netlib dtoa.c from https://netlib.sandia.gov/fp/dtoa.c
Jesper Lundgren
committed
Rename strtod to fpconv_strtod
Jesper Lundgren
committed
Update MALLOC definition to match new dtoa.c
Jesper Lundgren
committed
Add custom pthread based dtoa pool
Jesper Lundgren
committed
Set fairly large pool size based on the core count
Jesper Lundgren
committed