Remove tabs from source files

Tabs accidentally crept into source files in violaton of the style guide

Signed-off-by: Steve Bennett <steveb@workware.net.au>
Add regression test for return -code eval

Signed-off-by: Steve Bennett <steveb@workware.net.au>
tailcall: properly merge tailcall frames

Resolve the tailcall command immediately in [tailcall] and stash it.

If a tailcall is currently being evaluated, new tailcalls in the same
frame are merged/deferred to evaluate in the same C stack frame.

Can't merge tailcall evaluations across uplevel.

Add some tests for these cases

Signed-off-by: Steve Bennett <steveb@workware.net.au>
Revert "Better handling of dict hash tables"

This reverts commit 5155f363872af642ade631396d1d7303285c3481.

It seems that this change has made dict element addition slower,
so revert it.

Signed-off-by: Steve Bennett <steveb@workware.net.au>