Support "none" in all configuration strings as an alternative to an
empty string. Reference #1417.
Merge branch 'develop' into none-config
The initial byte comparison has to be case-independent as well.
Eviction has its own directory, replace __rec prefixes with __evict,
they're a holdover from when reconciliation and eviction were joined.
Check for configurations of "none" in a wrapper around the config string parser.  There is some code that looks for explicit "none" strings (such as statistics configuration), and overriding "none" in all cases scares me.
More docs for "none" configs.
Clarify the documentation of WT_ITEM fields.
Merge branch 'develop' into none-config

Conflicts:
	dist/api_data.py
Merge pull request #1431 from wiredtiger/none-config

None config
Rebuild auto-generated files.
Reinstate the log.prealloc config that was lost during a merge.
Merge branch 'develop' into force-evict-many-deletes