Ability to treat comments as code

[timothycrosley]

isort should allow treating all single line comments (or chosen single line comments) as code if that is the end users preference.

For example:

import b

# these are special imports that have to do with installing X plugin
import c
import a

by default isort would turn this into:

# these are special imports that have to do with installing X plugin
import a
import b
import c

with the new treat_all_comments_as_code option turned on it would become:

import b

# these are special imports that have to do with installing X plugin
import a
import c

[timothycrosley]

This supersedes: #1338

[timothycrosley]

This has been released with version 5.3.0 of isort