Sorting order of locations is wrong way round

[tvdstorm]

When sorting a collection of locs, the result goes from larger to smaller.

Reproduce:

l1 = |scope:///|;
l2 = |scope:///shut|;
l3 = |scope:///shut/nested|;
l4 = |scope:///bla/nested|;
sort([l1, l2, l3, l4]) // => 

[
  |scope:///bla/nested|,
  |scope:///shut/nested|,
  |scope:///shut|,
  |scope:///|
]
``

[jurgenvinju]

It looks like the double dispatch on SourceLocationResult for lessThen does not re-invert its parameters.

[jurgenvinju]

Since typepal and the Rascal checker depend on source location semantics, let's tred carefully and first find out where < and > on source locations are being used.