added request filters and more versatile logging. See GH-68, GH-65, GH-31
log js console messages only on verbosity level 2
Merge branch 'master' into request-filters-and-logging.
Fix test_request_filters to be compatible with master.

Conflicts:
	splash/tests/utils.py
add support for default request filter rules
rename "request filters" to "request middleware" to avoid confusion with Adblock filters
Merge branch 'master' into request-filters-and-logging
DOC document request filters
DOC fix Adblock Plus URL
warn when adblockparser or pyre2 are needed, but not available
debian packaging: /etc/splash/filters folder
Merge branch 'master' into request-filters-and-logging
improved logging for loadFinished signal
add microseconds to log
Merge branch 'master' into request-filters-and-logging
log more events
log more QWebPage/QWebFrame events
aboutToBlock/await logging
Merge branch 'master' into request-filters-and-logging

Conflicts:
	splash/qtrender.py
	splash/tests/utils.py
Merge branch 'master' into request-filters-and-logging

Conflicts:
	splash/qtrender.py
Merge branch 'master' into request-filters-and-logging

Conflicts:
	splash/defaults.py
	splash/tests/utils.py