Added possibility to limit the amount of data retrieved

[daigo75]

Ref. feature request #137.

Usage example

$Response = \Httpful\Request::get('http://somesite.com')
    ->limit(1000) // Limit the amount of bytes retrieved
    ->send();

[daigo75]

Note: the coding style used for the library is different from the one I normally use, therefore you might need to make a couple of adjustments.

[nategood]

Hi @daigo75. Please convert the spacing in here to spaces as opposed to hard tabs for consistency. Thanks!

[daigo75]

I forgot, my editor is set to tabs (never liked spaces much, too rigid). I will review the files and make the conversion.

By the way, technically, spaces are hard indentation, while tabs are a soft one (two spaces are always two spaces, while tabs can be displayed as 1, 2, 3 or more). :)

[daigo75]

Done! Tabs are now spaces.