Updadte example commands

Show test results at the end

Fix preview for small images

Create a logfile for each testcase

More testing

Show testcase number in the output

Fix testcase argument expansion + add more tests

Update usage section

Fix sharpening defaults + add option for sharpen radius

Fix a typo

Update usage section

Ignore test output images

Add error checking and attempt fixing test output ignoring

Add tests

Add gitignore for tests