Support for multiline comment for header

[sammyne]

Is your feature request related to a problem? Please describe.
A clear and concise description of what the problem is. Ex. I'm always frustrated when [...]

Some situation using golint will enforce max column width (e.g. 100 or 120), which will trigger warning for too long comment for fields like header.
Multiline description has been supported thanks to PR#219, so it would be nice to support multiline comment for these fields' comments if possible.

Describe the solution you'd like
Support multiline comment for these fields' comments if possible.

That is,

@header 200 hello "how do"
@header 200 hello "you do"

will be equivalent to

@header 200 hello "how do you do"

[ubogdan]

Hi @sammyne,
Since this is a feature request and there are several issues waiting to be fixed, I really don't think we can implement this somewhere soon. If you have some spare time please contribute with a PR.

Looking forward to seeing your implementation.