Use PHPStorm to reformat code in HTTP.php as exemplar.

Some changes:
 * Remove trailing space
 * Standardise spacing inside functions
 * Prefers tabs over large number of spaces
 * Deprecate single line if-statements, per general MediaWiki consensus

My choices have been guided by existing practice, rather than my
own personal preferences or indeed MediaWiki house style per se.

One error had to be fixed manually:
   if( ... ) global $foo;
was misunderstood by PHPStorm. Otherwise, easy to repeat/tweak if we
want to settle on a different standard. Otherwise, it's easy to roll this
standardisation out across Peachy.