Splash UI: allow to download network activity as .har file. Fixes GH-325.
Splash UI: allow to download network activity as .har file. Fixes GH-325.

pawelmhm/splash,Youwotma/splash,pawelmhm/splash,Youwotma/splash,pombredanne/splash,pawelmhm/splash,pombredanne/splash,Youwotma/splash,pombredanne/splash