support any http options

[microcai]

http options is implemented as number of classes. Is there any reason not to use a k/v based container ?
If I want to add more options, I HAVE to change the source code. That makes urdl less adaptable to regular uses.

[WoLfulus]

+1

[canselcik]

Agreed. I wish there was another non-libcurl HTTP client for C++. Customizing the host header requires modifying the source code.