iterators now return tyIter(T);

tyIter(T) represents an "iteration yielding values of type T"

I'm planning to use that in the context of the `is` operator
supporting predicates such as `C.items is iterator` and also
in the upcoming support for higher-order inline iterators.
zmq: remove unnecessary 'var' decls from high-level procs
Add type-specific allocation procs.
Add missing cast.
Add allocation unit tests.
Merge branch 'devel' into alloc-overloads
Merge pull request #977 from EXetoC/alloc-overloads

Allocation overloads
split the inline and closure iterators into different symbol kinds for easier discrimination between them
Merge pull request #975 from zielmicha/zmq-fix

zmq: remove unnecessary 'var' decls from high-level procs
test cases for the new handling of iterators by the `is` operator
Added comment explaining 'assert_numbits' error.
Merge pull request #978 from ReneSac/devel

Added comment explaining 'assert_numbits' error.
fix #587
Merge branch 'devel' of github.com:Araq/Nimrod into devel
implements strongSpaces parsing mode
Merge branch 'devel' of https://github.com/Araq/Nimrod into devel