Get the scheme execution environment
Restructure evaluation in the guile code

..so that we'll be able to set environment
iActually pass the environment
Make proper use of environment for all evals
Explicitly provide the atomspace to scheme

This ia another step enabling muulti-atomspaces
Merge pull request #701 from linas/multispace

More preliminary steps to multi-atomspace support in scheme
Fix memory management bug

... which we are hitting only due to other redesigns.
Merge pull request #702 from linas/multispace

Fix memory management bug
At last - a mostly-working mutli-atomspace scheme
Fix annoying bug regarding output ports
Go back to an earlier style of doing things

The environment/module thing was a faulty idea that couldn't have worked.
clean up cruft from the previous round of changes
Expand the multi-atomspace unit test
Expanded the multi-atom-space unit test
Merge pull request #703 from linas/multispace

Multiple atom spaces now work in scheme