fixed some case insensitive matches

removed redundant line

Version number updates for 0.15.3 release.

Update CHANGELOG.md

added changelog for 0.15.1

Last minute bug cleanup on file extensions.

This is the result of my checking the Volume vs Archive
behavior, and discovering a few weird edge cases where
running a sub-program from a program behaved differently
from running a program from command-line.

Also tested that the logic of compiled vs source running
is all good, and made a few tweaks to get that working.

bumped version to 14.2

added RotationalPeriod per request of Joe32320

updated promo image

fixed dependency issue KSP-KOS#199