Test format stress aborts with out-of-order returns

[1479441997:536475][11459:0x7fc6fca60700], t, file:wt, WT_CURSOR.prev: WT_CURSOR.prev out-of-order returns: returned key 94544 then key 94567: Invalid argument

[1479441997:536536][11459:0x7fc6fca60700], t, file:wt, WT_CURSOR.prev: the process must exit and restart: WT_PANIC: WiredTiger library panic

[1479441997:536544][11459:0x7fc6fca60700], t, file:wt, WT_CURSOR.prev: aborting WiredTiger library

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#  RUN PARAMETERS

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abort=0

auto_throttle=1

backups=0

bitcnt=8

bloom=1

bloom_bit_count=6

bloom_hash_count=14

bloom_oldest=0

cache=48

checkpoints=0

checksum=uncompressed

chunk_size=8

compaction=0

compression=none

data_extend=0

data_source=file

delete_pct=9

dictionary=0

direct_io=0

encryption=none

evict_max=5

file_type=variable-length column-store

firstfit=0

huffman_key=0

huffman_value=0

in_memory=1

insert_pct=7

internal_key_truncation=1

internal_page_max=17

isolation=read-uncommitted

key_gap=2

key_max=32

key_min=26

leaf_page_max=9

leak_memory=0

logging=0

logging_archive=0

logging_compression=none

logging_prealloc=1

long_running_txn=0

lsm_worker_threads=4

merge_max=8

mmap=1

ops=100000

prefix_compression=1

prefix_compression_min=5

quiet=1

repeat_data_pct=33

reverse=0

rows=100000

runs=100

rebalance=0

salvage=0

split_pct=83

statistics=0

statistics_server=0

threads=25

timer=20

transaction-frequency=32

value_max=80

value_min=1

verify=0

wiredtiger_config=

write_pct=44

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