Revert to clearing all pages from the LRU queue: change 81d7c81584a1ffcc4d8b6912403c17ff97884767 fails this assertion:
btree/bt_discard.c, 45: !F_ISSET_ATOMIC(page, WT_PAGE_EVICT_LRU)

refs #735
Merge branch 'develop' into fine-grained-durability