atomspace: remove some dead code
atomspace: final removal of IncomingSet from Atom

Remove the getIncomingSet() from the atom. This is now
handled as just another index on the atom table.
atomspace: remove silly ineffeciency
atomspace: remove pointless check

By definition, an atom in an index is always in the atom table.
It is pointless to check to see if it is there.
benchmark: no single-letter names

Its nearly imposible to grep single-letter names.
atom space benchmark: no single-letter names
oops, missed one spot which used the old method
benchmark: measure AtomTable too.

Add everything needed to measure raw atomstable performance.
Add performance diary for the benchmarks
iAdd more analysis to the diary
Merge pull request #128 from linas/outgoing

More IncomingSet cleanup, and baseline perf measurements

Merging; this is straightforward stuff; all unit tests pass.