Classlib: Rest: Allow streams/functions as a Rest's value
Classlib: Pcollect: Apply 'processRest' to result of collect func

Necessary because the collect func may return a Rest.
Previously, this Rest was not 'process'ed, breaking
math operations on the return value.

At first, I thought this might also be needed for
Pselect and Preject, but these patterns only suppress
output values, not alter them. Rests should already
have been 'process'ed by the input stream.
Merge pull request #941 from jamshark70/topic/hjhPatternRestFixes

Classlib: Fix 2 issues regarding Rest and patterns