vibe.d sockets support

Support for vibe.d sockets.

more performance optimizations; removed unnecessary log message

More .dup removed; more refs returned to avoid data copy
Unnecessary error log removed from exception handler.

many performance optimizations

Many performance optimizations: avoided memory copy and allocations when possible, internal loops optimized.

Streaming response for HTTP and FTP; performance emprovements.

• Streaming response from server. Caller consume InputRange while receiving data from server.
• Performance emprovements. Several data copy avoided. Minor performance tests executed.

more clean interface for getContent and postContent

more simple interfaces for getContent. Clean form submission and file upload interface for postContent. Yet another windows libssl/crypto linking fix.

Cookie handling added

Minimal cookie handleng added: no persistency(but you can get and set cookie for Request), no expiration.

Added ftp. Some bugs fixed.

Added ftp. Some bugs fixed.

file package.d missed

file package.d missed

fix some tests

fix some tests

win32 ssl/crypt libraries added

win32 ssl/crypt libraries added