* Split out proxy headers and moved to public API to allow external
modules to be built.
* Split proxy into proxy library and proxy binary. The library
can be used by other applications and provides a simple API
* Improved channel passthrough, now all channels including dynamic
channels work.
* Extended module API to hook more events, improved module samples
* Cleaned up proxy code, removed global static variables used,
added WINPR_ASSERT
RDPSND channel is special, as it has many names.
(e.g. static channel, dynamic channel and UDP one.
Use RDPSND_CHANNEL_NAME to identify the module name instad of
RDPSND_DVC_CHANNEL_NAME
Proxy server might receive input updates while client side being
redirected (and reset), then a heap-after-free might occur. To solve
this, we register server input/update callbacks only after client is
fully activated.
* Add support for C++ plugins.
* Seperate between a "module" and a "plugin": a module is a shared
library that exposes a function called "proxy_module_entry_point". This
function gets a parameter to `proxyPluginsManager*`, which can be used to
register plugins.
* Refine the API of the modules infrastructure:
* use proxyData* instead of rdpContext* when firing a hook or calling a filter.
* use clearer names.
* Instead of having to specify a path for each module to be loaded in
the configuration, the proxy now loads modules from specificed
directory, using the CMAKE variable PROXY_PLUGINDIR.
* Add an option to specify required plugins: plugins that the proxy
wouldn't start without having them fully loaded.
Because the proxy uses freerdp_settings_copy to do re-negotiation after
first connection to remote server, all redirection information
(RedirectionPassword, RedirectionDomain, etc.) pointers were duplicated
(to both client and server settings structs). Then, at disconnection, a
double-free occured.
