15. The computer-readable storage medium of claim 14 , wherein performing the accelerated merge comprises: identifying which data units of the first document match data units of the second document by comparing unique, persistent identifiers of each data unit of the first document to unique, persistent identifiers of each data unit of the second document; inserting the identified data units into the merged document directly to create data units of the merged document; and merging each data unit of one of the first and second documents that does not match any data unit of the other of the first and second documents using a conventional merge to further create the data units of the merged document.
15. The computer-readable storage medium of claim 14 , wherein performing the accelerated merge comprises: identifying which data units of the first document match data units of the second document by comparing unique, persistent identifiers of each data unit of the first document to unique, persistent identifiers of each data unit of the second document; inserting the identified data units into the merged document directly to create data units of the merged document; and merging each data unit of one of the first and second documents that does not match any data unit of the other of the first and second documents using a conventional merge to further create the data units of the merged document. 16. The computer-readable storage medium of claim 15 , wherein comparing the unique, persistent identifiers of each data unit of the first document to the unique, persistent identifiers of each data unit of the second document comprises: comparing a unit identifier and an edit identifier of each data unit of the first document to a unit identifier and an edit identifier of each data unit of the second document.