lib: code style and optimization proposals

[tshemsedinov]

About eslint message Unexpected parentheses around single function argument having a body with no curly braces arrow-parens: I propose to use () around single argument when we declare method or it have multi-line body, it's for readability. If we pass lambda as parameter and it's short we fon't need () of course.

[belochub]

@tshemsedinov, this eslint rule was discussed and added in https://github.com/metarhia/jstp/pull/122, check out that thread. How exactly do you propose to change this rule in .eslintrc file?

[tshemsedinov]

@belochub thanks, may eslint detect multi-line lambdas?

[tshemsedinov]

Reverted change: lambda wrappers on export are back again

[lundibundi]

@tshemsedinov can you please use 'fixup' for incremental changes in the PR as it's very hard to understand the exact changes after force-push especially in somewhat big PRs?

[aqrln]

Landed in 45bb40f14a4dcd91c778b457ddb7b0a18db843b5.