Version 1.1.0-beta2

Allow images tool to delete images

Version 1.0.1a

Finalize merge of `layers` branch

Closes MFEK#5.
Closes MFEK#8.
Closes MFEK#12. (src/tools/pan.rs documents Tool struct)
Closes MFEK#13.
Closes MFEK#21.
Closes MFEK#27.
Closes MFEK#64.
Closes MFEK#100.