Making reload_time in LiveReloadHandler.poll_tasks configurable

[Lucas-C]

Use case

I use the following watch_and_serve.py script:

#!/usr/bin/env python3

from os.path import dirname
from livereload import Server
from other_module import gen_css_bundle

SERVER = Server()
SERVER.watch('index.html')
SERVER.watch('assets/css/main.css', gen_css_bundle)
SERVER.serve(root='.')

The gen_css_bundle function takes a few milliseconds to execute and edit index.html to insert the new bundle filename.

When I run this script and edit main.css, I see the following logs:

[I 210327 10:57:21 watcher:104] Running task: gen_css_bundle (delay: 3)
[I 210327 10:57:21 handlers:95] Reload 1 waiters: ./assets/css/main.css
[I 210327 10:57:22 handlers:82] Ignore: ./index.html

I want to introduce a mechanism in livereload in order to control this "ignore" logic,
so that in my case the brower is reloaded once index.html has been edited by gen_css_bundle.

Suggested solution

Hence, this PR introduces a livereload.handlers.LiveReloadHandler.DEFAULT_RELOAD_TIME class constant,
that can be used this way:

#!/usr/bin/env python3

from os.path import dirname
from livereload import Server
from livereload.handlers import LiveReloadHandler
LiveReloadHandler.DEFAULT_RELOAD_TIME = 0  # do not ignore index.html edition by gen_css_bundle and trigger browser reload
from other_module import gen_css_bundle

SERVER = Server()
SERVER.watch('index.html')
SERVER.watch('assets/css/main.css', gen_css_bundle)
SERVER.serve(root='.')