constrain -> constraint

Signed-off-by: Sam Kleinman <samk@10gen.com>
DOCS-2618: improve navigational context
DOCS-2251: adding new fields to output of replSetGetStatus output
DOCS-2453: adding diaglog deprecation notice
DOCS-2141: adding basic documentation
DOCS-2352 sparse index 2.6 change
DOCS-2319 2.6 restricts sort specification values
DOCS-2372 copydb works with auth in 2.6
DOCS-1948 index key length restriction and fix calc of index key size
DOCS-2544 add bulk apis
DOCS-2595 index filter commands

Conflicts:
	config/htaccess-next.yaml
DOCS-2464 changes to 2.6 downgrade and upgrade
DOCS-2613 audit parameter change
DOCS-2613 for audit filter option, remove the config file examples
Update data-model-operations.txt

Grammar updates and one clarity update.

Signed-off-by: kay <kay.kim@10gen.com>
fix line length of pull request merge
Update indexes-introduction.txt

Signed-off-by: kay <kay.kim@10gen.com>
BUMP 2.5.5
Update index-single.txt

Signed-off-by: Sam Kleinman <samk@10gen.com>
index-single: edits