Add support for LSM column groups and indices to the schema layer.
Merge branch 'develop' into lsm-schema
Merge branch 'develop' into lsm-schema
This function solves a problem in reconciliation. The scenario is:
	-  a leaf page that references an overflow item
	-  the item is updated, creating a WT_UPDATE chain
	-  the update is committed
	-  a checkpoint runs, freeing the backing overflow blocks
	-  a snapshot transaction wants the original version of the item

In summary, we may need the original version of an overflow item for a
snapshot transaction, after it's been deleted from the checkpoint tree.
We don't have any way to delay a free of the underlying blocks until a
particular set of transactions exit, and this isn't a common scenario:
read the original overflow item and stash it at the end of the WT_UPDATE
list with a transaction ID guaranteeing no reader will go past the entry.

Reference #310.
Merge branch 'develop' into bug.310
Merge branch 'develop' into bug.310
Merge branch 'develop' into bug.310
Merge branch 'develop' into bug.310
Fix the oldest snap_min calculation when starting a transaction.
Update our copy of the oldest snap_min before deciding whether to read an old overflow item.
whitespace
Merge branch 'develop' into bug.310
Merge branch 'develop' into lsm-schema
Fix a bug in LSM - we were copying too many entries when doing minor
merges.
Merge branch 'bug.310' of github.com:wiredtiger/wiredtiger into bug.310
Merge branch 'develop' into bug.310
whitespace
Merge branch 'develop' into bug.310
Create fake checkpoints until an object is modified, so that a checkpoint
between the cursor create and the bulk load doesn't make it impossible to
do a bulk-load on the cursor.  Closes #338.
Merge branch 'develop' into bug.310