imported patch multiple-eviction-threads
Only try to allocate memory for eviction workers if they are configured.
Merge branch 'develop' into multiple-eviction-threads
Merge branch 'develop' into multiple-eviction-threads
Merge branch 'develop' into multiple-eviction-threads

Conflicts:
	src/btree/bt_evict.c
Merge branch 'develop' into multiple-eviction-threads
Take the cache size into account when calculating the maximum size of a page in-memory.  Use that calculation in the decision to deepen internal pages.

refs #486
Disable prefix compression by default.
Merge branch 'develop' into multiple-eviction-threads
Minor shuffling of prefix-compression docs (now that prefix-compression
is off by default, the example should be turning it on, not off).
Use the value of the "leak_memory" config item, not its length, to determine whether it is set.

refs #845, #982
Don't run the leak-memory code, it upsets valgrind.
Merge pull request #981 from wiredtiger/prefix-compression-default

Disable prefix compression by default.
Don't mention valgrind by name, it makes spell check sad.
Implement review feedback for #980.
typo
Merge pull request #918 from wiredtiger/multiple-eviction-threads

Support multiple eviction threads
src/btree/bt_evict.c:174:3: error: conversion to 'int' from 'u_int' may change the sign of the result [-Werror=sign-conversion]
Make the upper bound on the maximum page size work with shared caches: if the cache size hasn't been set when creating the table, ignore it.

refs #980
Merge pull request #980 from wiredtiger/deepen-small-cache

Take the cache size into account when calculating the maximum size of a page in-memory