Allow choice between spatial & spectral searching

[MatthewWhiting]

We currently just do the searching spatially, one channel map at a time. IWBGTH the ability to request the search be done spectrally, one spatial pixel at a time instead.

This would just be a simple input flag (flagSearchType perhaps?).

Then rename search3DArraySimple to search3DArraySpatial and make a spectral equivalent (take it out of the search3DArray function). There'll need to be a new search3DArray function that acts as a switch depending on the value of the new parameter.

[MatthewWhiting]

Need to make the change in the normal searching, as well as reconsearch and smoothsearch.

[MatthewWhiting]

Done in [686]. Leave this open while I check the effects.

[MatthewWhiting]

OK, it seems to work alright. You get the same results with spatial or spectral searching provided you do the rejection after the growing & merging.

If you do it before, some source may be large enough from one search (because there is the intermediate merging) to make it through, but not with the other search type.

Perhaps it is worth adding another option to switch off the intermediate merging?

[MatthewWhiting]

Done in [691] - works quite nicely, although complex interplay between it, the rejectBeforeMerge and the two rejection parameters...

Anyway, ticket closed.