IDEA-131621 IDEA 139.144.2 takes forever to start. Hangs on 100% splash screen state
(cherry picked from commit 16f81a9)
inline UpdatesXmlLoader
(cherry picked from commit 3f40aa3)
UpdateChecker — use platform timeout defaults (5 sec connection timeout could be not enough even in normal case)
(cherry picked from commit b806454)
cleanup
(cherry picked from commit 1d20c54)
cleanup
(cherry picked from commit 831ba12)
cleanup, progress indicator nullability
(cherry picked from commit d924786)
cleanup
(cherry picked from commit 6729665)
cleanup
(cherry picked from commit 73c2ce1)
Use HttpRequests to fix IDEA-131621

checkPluginsHost — don't load twice versions info (we still parse it twice)
ensure that we download plugin under determinate progress
(cherry picked from commit e402e8a)
cleanup
(cherry picked from commit e7f20c8)