added a ``noforward`` pragma that enables a new compilation strategy
not requiring forward declarations on a per-module basis
switch to a linked list of scopes
get rid of the SymTab* procs in astalgo
get rid of ImportTablePos and ModuleTablePos
get rid of TOverloadIter.stackPtr
final fixes giving us a working compiler
merged the persistent scopes work with the delayed proc compilation strategy
documented the ``noforward`` pragma
Merge branch 'master' of github.com:Araq/Nimrod into upstream