Break out stages into public functions

Signed-off-by: Robert Günzler <r@gnzler.io>

Refactor into library

Signed-off-by: Robert Günzler <r@gnzler.io>

Add screenlocker

Signed-off-by: Robert Günzler <r@gnzler.io>

Add script that can convert to jpg

Signed-off-by: Robert Günzler <r@gnzler.io>

Fix README.md typo

Fix build by adding go.mod, update README.md

Recompressed shots with pngcrush (-5MB difference)

Merge branch 'marcospb19-master'

Quick fixes to the README.md

Adding more examples

Renaming shots/ files

Adding new aur package info (corrupter-bin)

Also adding extra explanation about corrupter

Merge pull request #8 from nodiscc/os-stderr

use os.Stderr instead of flag.CommandLine.Output

use os.Stderr instead of flag.CommandLine.Output
this fixes compilation on golang 2:1.7~5 (Deian 9 stretch)
Fixes https://github.com/r00tman/corrupter/issues/7

Use NRGBA instead of RGBA for intermediate images (issue #6) (1.6s -> 1.2s on 3000x2000 images, since encoding is now essentially free)

Disable png compression (issue #6) (3.6s before, 1.6s after on 3000x2000 images)

Update README.md

Update README.md

Create LICENCE (issue #5)

Change default -add (brightness) to match the initial version (and the examples)