Refs #2935, add installation UI test, allow no fixture to be specified for screenshot test and fix following installation process regressions:

- pending events should be executed after all plugins successfully loaded so plugin order in config file is unimportant
- do not set piwikUrl on View instances if the DB cannot be connected to
- create Twig instance when clearing template cache instead of new View
sorted tests
fix #4796 anchor links do not work after merging AngularJS
Merge branch 'master' of github.com:piwik/piwik
Refs #2935, fixing Installation UI test.
Updating UI submodule.
Adding missing test file
Updating submodules.
Fixing bugs in screenshot testing lib.
Add log output when line invalid and replaying log
Refs #3632 Adding more tests cases for log replay functionnality
Forcing all recorders and recorders max payload to 1, to prevent random behavior (eg. in Live.getLastVisitsDetails, the pageIdAction may be random order if recorders import data in random thread order)
Submodules
Adding missing test files
Refs #3632 test case that _idvc > 1 will set visitor returning status
Refs #3632 Creating a test case: same visitor (same IP + idvisitor) visits the website on two different days.
Visitors on second day is marked as "new" because window_look_back_for_visitor is not set.
Move SqlDump fixture from Bencharmks dir to Fixtures dir, fix bug in core/Updates.php, tweak test environment setup and update UI submodule.
Fixing build.
Fixing build.
Refs #3632 New test case: replaying logs and forcing a window look back (forceLargeWindowLookBackForVisitor=1)
=> The visitor is now marked as "returning" as expected
Updating expected tests files