add saturate(…) functions + cast consistency fixes
add FileDescriptor::fstat(…) function
add Sink::finish()
add Tee
move compare_ci(…) into new header file ci.h
replace HttpHeaders.split(…) with HttpHeaders.find_token(…)
add Buffered{Source,Sink}
add DelimitedSource
add Chunked{Source,Sink}
move Http{,s}Connection to webclient.{h,cpp}
add GZip{Source,Sink}
add LimitedSource
add optional gzip support to HttpConnection (-DHTTP_GZIP)