added timestamp to resource table.

fixed bugs in transaction and resource tracking recording.  Transaction and
transfered resource data must be recorded AFTER resource is extracted from
supplier and BEFORE resource(s) are added to requester.
cleaned up resource buf interface. Added some basic templating to eliminate need for separate mat_buff
Merge branch 'better-buf' of github.com:rwcarlsen/cyclus into rwcarlsen-better-buf
changed resource creation to take this ptr instead of context ptr. Removed
context arg from Material::CreateUntracked. Made untracked resources have an id
of zero instead of an id of garbage. fixed mat doc comments to use new res_buf method names.
Merge pull request #626 from rwcarlsen/res-this

changed resource creation to take "this" ptr instead of context ptr.