Write a new version of config-collapse that merges nested structures
so reconfiguration doesn't lose previous configuration information.
Reference #1172.
Merge branch 'develop' into collapse-nested-structures
Create __wt_config_merge for the merge functionality, called only
from reconfigure at the moment.  Clean up some comments, explain
how config-collapse and config-merge differ.
Messed up the test for a separator character (dot) in the key, the
check has to appear before we build the key we're using for the merge.
Statistics logging requires a wait time, reference #1172.
config_collapse.c:156:12: error: assignment discards 'const' qualifier
from pointer target type [-Werror]
config_collapse.c:158:5: error: format '%s' expects argument of type
'char *', but argument 4 has type 'const void *' [-Werror=format=]
typo
Statistics logging of sources only currently supports lsm: and file: URIs.
The wiredtiger_open final config array contains multiple entries (the
defaults, the config file, the environment variable and the
application-supplied config), merge them instead of collapse so we don't
lose fields in nested structures.
Merge pull request #1205 from wiredtiger/collapse-nested-structures

Implement merging of nested configs for connection reconfigure.