RoelTyper - small fix

TypeCollector class >> newForPlatform is making reference to a deprecated
method (Smalltalk version). Below is the fix.

Cheers,
Francisco

newForPlatform
 "Return either a VWTypeCollector or a SqueakTypeCollector, depending on the
platform used."

 | versionString |
 versionString _ SystemVersion current version.
 ('*Squeak*' match: versionString)  ifTrue: [^SqueakTypeCollector basicNew].
 ('*VisualWorks*' match: versionString)  ifTrue: [^VWTypeCollector
basicNew].
 ^self error: 'Unsupported Platform!'