This hugely reduces the number of exports, making it acceptable for
browsers.
Note that dlink + threads is still not working due to upstream issues
with the pthread emulation library.
Should hopefully be solved once emscripten move to native WASM threads.
You can now run the test HTTP server by calling:
scons p=web serve
If you also wish to run the browser, call instead:
scons p=web run
The default listen port is 8060, but can be overriden via the env
variable GODOT_WEB_TEST_PORT which must be a valid integer.
Update export names (web[_dlink]_[release|debug].zip).
The Build with dynamic linking is broken due to high number of imports
in output wasm (likely emscripten regression issue 15487).
