make global image types operations list for bash scripts

[earthbound19]

Store a list of all supported file formats for many image operations (in many scripts) in the bash user dir (~/), and make an array from that for those scripts (instead of maintaining it hard-coded in so many scripts, which is failing and they all have different lists).

Affects at least these scripts; checkmark ones you verify are updated to use it or you have verified it is n/a:

• [x] allToOldestWindowsDateTime.sh
• [x] gm_downsize_img_copies_to_smallest.sh
• [x] archiveMetadataWin.sh
• [x] exportIMGsMetadataSimple.sh
• [x] diff_avg_supercomposites.sh
• [x] diff_avg_supercomposites_nested_loop.sh
• [x] fixIMGnames.sh
• [x] archiveMetadata_updateFrom_devtools-slash-scripts--what does that mean.sh
• [x] ~dateByMetaDataIMG.sh~ dateByMetaDataMastersOnly.sh
• [x] dateByMetaDataMastersOnly.sh

~get_all_imgs_array.sh~ (see #103)

[earthbound19]

New script to do this is makeImageTypeOperationsList.sh, but work may already be done by get_all_imgs_array.sh (which has a far better name anyway)! If so use that latter and delete the former!

[earthbound19]

yes work already done by that; deleted new script; closing.