Attempt at normalistion of comparison styles - empty string on left and right hand...

Attempt at normalistion of comparison styles - empty string on left and right hand side normalised to it being on the rhs

Before this change, there were (? being regex 0 or 1)

"" ===? 1
'' ===? 24
"" !==? 8
'' !==? 32

== "" 14
== '' 344
!= "" 9
!== "" 4
!= '' 151
!== '' 85

Rhs was the much more common, and the preferred style by many developers.. (Was a similar discussion in #mediawiki recently.. After that lolbugreport i think)

Where there is a string (non empty) on the lhs, and variable/method call on the rhs still need normalising