Order of items in inbetween face's cycles not preserved when opening then saving

[dalboris]

If you open a file containing inbetween faces, and save this file without any modifications, then the XML value for the cycles attribute of inbetweenface elements might be different from the original file. More precisely, the nodes in the cycles may be assigned different indices, making it hard to compare.

Example:

cycles="[1:(42+,3,2,_,_) 2:(43+,1,3,_,_) 3:(44+,2,1,_,_)]"

may become:

cycles="[1:(43+,2,3,_,_) 2:(42+,3,1,_,_) 3:(44+,1,2,_,_)]"