Initial merge investigation

OK, this PR now contains only one thing, which is a code change from Kehan that requires further discussion.

(Still don't merge it, we don't want 28 commits for this, we can put it on another branch and commit it cleanly, then close this PR)

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Previous description:


DO NOT MERGE THIS YET.

This is an investigative PR to see what the diffs are between the WAM version and the CA version. Each change when ready should be put into a separate PR on a separate branch and merged in to one or both of the upstream repos.

UPDATE: Some of the separate branches have been merged into wamuseum:master and there are pull requests for collectiveaccess:master (see https://github.com/collectiveaccess/providence/pull/96, https://github.com/collectiveaccess/providence/pull/97, https://github.com/collectiveaccess/providence/pull/98).  What's left in this PR are three things: 

* the WAMMultipartIDNumber.php file
* one code change which is still under review (OpenLayers.php)
* "local" stuff which will never be pushed up to the collectiveaccess fork (only to wamuseum)

ALSO NOTE: The /app/conf/local directory is in .gitignore and therefore cannot be committed, how we deal with this is still in consideration.