Changes since tag v20

commit ab52331c7378878e8dbf2c6716ac95710be0a69f
Author: (rowaasr13) Oleg V. Volkov <rowaasr13@gmail.com>
Date:   Sat Mar 20 08:00:16 2021 +0300

    reorder some calls for better profiling

commit f183f6f28b533fb47f2cee76900ef4cb9aa10cad
Author: (rowaasr13) Oleg V. Volkov <rowaasr13@gmail.com>
Date:   Sat Mar 20 07:59:36 2021 +0300

    drop string.match, use string.find as it should've been from beginning to reduce garbage generation (I can't remember how many times I've misused it that way already)

