Blender Git Loki

Partial fix for array modifier vertex merge (bug 30195).

Two fixes:

* The find-doubles operator was overriding the "dirty" element
indices, so vertices were not being mapped correctly.

* In some cases a vertex can be set to merge with a vertex that is
also set to be merged, so added a loop to find the first unmerged
vert in this case.

Not yet working is the "First Last" merge option.

Also made some cleanups and added comments in the array/remove doubles
code.