Replace hard-coded “http://” protocol with newly-available “$_SERVER[HTTP_PROTOCOL]”
More code style conversion to always use { and }, minor improvements

Continue what commit 8caae3f672b20b407eac2e904471b0940358e701 started.

Also improve some comments and a long preg_replace() replacement
expression.
Improve QlApplication startup, “load_modules” moved to boostrap.conf

Avoid unnecessary array manipulations when we know that $_APP is
completely empty.

Move to QlApplication::__construct() the adjustment of “core” entries
loaded from bootstrap.conf.
Add [DESIGN_8261 QlApplication]

Document importance of QlApplication and how its early availability is
achieved.