Simplify a test for WT_BTREE_BULK, if the flag is set, we're done.
Don't use S2C() where we already have a local variable.
Simplify bulk-load flags vs. eviction, make it bulk-load's problem,
not eviction's.

Eviction doesn't look at files that aren't open (WT_DHANDLE_OPEN not
set), which I believe means WT_BTREE.root.page should never be NULL.
Further, eviction shouldn't know anything about bulk-load, remove the
bulk-load test, we'll use the WT_BTREE_NO_EVICTION instead.

Change the btree open function to set WT_BTREE_NO_EVICTION on an empty
object, at the same time we set the "bulk load is possible" flag.  As
soon as a row is inserted in the object, the bulk-load flag is turned
off, change the object's eviction status at the same time.

Change the cache-full check to skip checking the bulk-load flag, all
that needs checking is the eviction flag.

Minor paranoia change: don't let eviction be configured on the metadata
file.
Have LSM clear the bulk_load_ok flag for the primary, otherwise the btree layer will override the "no eviction" flag.
Merge pull request #1118 from wiredtiger/bulk-checkpoint

Bulk checkpoint changes