* 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
- fixed invalid, missing or additional arguments
- removed all type casts from arguments
- added missing (void*) typecasts for %p arguments
- use inttypes defines where appropriate
As building with -Wl,--no-undefined might cause issues when
combined with other linker flags (e.g. with -fsanitize=address see #3289)
it is now disabled per default but can be re-enabled with
-DWITH_NO_UNDEFINED=ON.
It is enabled for ci builds on linux to find undefined symbols.
