Fix $app connection in Register Method

Register method failed to get a copy of the Application for all uses.
Missing required second argument in array_diff

The $whiteListAttributes variable is missing on the comparison function. 
This pr corrects previous https://github.com/joomla/joomla-cms/pull/2575
Test using assertXmlStringEqualsXmlString instead of simple string comparison
Remove unnecessary php behavior check.
Reverting not allowing spaces in username
Preventing saving spaces at beginning and end of username for Superadmin
when installing Joomla
Clean up some webdriver tests to hopefully fix intermittent problems.
Merge pull request #2646 from infograf768/32883-new

# Reverting not allowing spaces in username
[#29791] Space inside extension manifest <updateservers> / server> xml
node caused unclear / confusing error message
Merge pull request #2577 from mariopro/patch-12

Missing required second argument in array_diff
Merge pull request #2620 from okonomiyaki3000/fix_travis

Test using assertXmlStringEqualsXmlString instead of simple string comparison
Merge pull request #1180 from AmyStephen/patch-1

Fix $app connection in Register Method of UsersControllerUser
Update stream.php ... Changed isSupported() method, now it returns false if allow_url_fopen is not set.
Revert "Update stream.php ... Changed isSupported() method, now it returns false if allow_url_fopen is not set."

This reverts commit 7e92195abf3f3aab2edb6191dbaa7620cc74eead.
[#32804] Broken bcrypt implementation and password handling improvements (Fix #2589)
[#32893] System information does not use the full width (Fix #2606)
[#31494] Layout parameter is loaded with wrong filter (Fix #1553)
[#32884] Missing space from administrator template <body> class declaration (Fix #2641)
[#32895] Fix E_STRICT notice in JFilterInput (Fix #2490)
[#32889] Version Note field is shown based on com_content settings for all extensions (Fix #2648)