* Updated the link to http-parser

 * Replaced signals/slots by Q_SIGNALS/Q_SLOTS
 * Added bool returns for write function so they don't silently fail
 * Added Q_UNUSED for some unused parameters in QHttpConnection

Removed the version of http-parser that was included here as it was outdated.
Added instructions in README.md to get the latest http-parser version
Fixed the code to follow http-parser changes (nodejs/http-parser@53adfac)

Modified the status codes to not be global and defined in the server
Fixed the missing url extraction

Added some sanity checks

The URL passed to QHttpConnection::Url includes the path and the query string, use
QUrl to parse this into components instead of using the whole string as the path.

…the associated TCP connection is disconnected.

The documentation for QHttpServer states QHttpRequest objects are never deleted by QHttpServer and that
the QHttpResponse is only deleted when end() is called.

This is not the case however if the TCP connection is disconnected before the reply has been delivered -
since the QHttpRequest and QHttpResponse objects are owned by the QHttpConnection that creates them and
QHttpConnection is deleted if the TCP connection is disconnected.  This can happen if the server
'parks' the QHttpRequest/QHttpResponse objects whilst waiting for data from another source before
sending back the reply - in our case, user input.

This commit adds a ref count to QHttpConnection to track the count of active users (QHttpRequest or
QHttpResponse objects).

The QHttpConnection is released when there are no active users AND the TCP connection is disconnected.

With this change, the onus is on the user of QHttpServer to handle all requests, otherwise they will
be leaked.  Previously they would have been 'leaked' only until the connection was closed.

…oyed if the associated TCP connection is disconnected."

This change caused two additional problems:

  * Any request/response objects not explicitly deleted are never freed which is a hassle for downstream
    consumers to have to deal with.

  * In addition to keeping the QHttpConnection alive, consumers also have to make sure they release
    any requests/responses before the QHttpServer is destroyed - since QHttpServer releases all connections
    when destroyed.

Instead, a simpler approach is to avoid holding on to dangling references downstream (eg. by using a QWeakPointer
or not holding on to a reference to QHttpRequest/QHttpResponse which could outlive the connection).

This commit instead keeps the old behavior but fixes the QHttpServer documentation about memory management.

This reverts commit caec4d3.

This returns the error from the underlying QTcpServer in the event of
a listen() failure.

MD-19113

Added serverPort() method returning the listening port of the server

MD-19537

This file never worked outside of a source tree that looked at least
very similar to the Mendeley tree.

Change {to,from}Ascii to {to,from}Latin1