Update HTML alias. Closes #1210.
Updates for the rename of the `HTML` facade.

See laravel/framework#1231
Merge remote-tracking branch 'upstream/develop' into develop
Merge pull request #1973 from bencorlett/patch-3

Updates for the rename of the `HTML` facade.
Move slash redirects to application level.
Use app_path in global file. Closes #1975.
Merge remote-tracking branch 'upstream/develop' into develop