[fpc-pascal] Improvement to TFPHTTPClient Class

[Michael Van Canneyt]

Hello,

This will not be applied, for 2 reasons:

1. The whole point of TFPHTTPClient is exactly to couple it to sockets
    framework (fcl-net).
    If you want to use synapse, use httpsend. lnet has a similar component
    for the http protocol.

2. I favour the opposite approach. Abstract out the underlying HTTP implementation
    at a higher level.

    For this I have introduced FPWebclient, which has 2 implementations:
    TFPHTTPClient and Synapse.

The new google-api and OData apis use FPWebclient.

Michael.