Set target as tag instead of ImagePresenter

allows us to remove an uneccessary map
Fix error replaced with standard placeholder

Only occurs when exception occurs synchronously
Refactor and add tests for ImagePresenter
- Updated the git ignore file.

Signed-off-by: Carlos Sobrinho <carlos.sobrinho@motain.de>
- If the config if null or any of the ARGB variants, save it as PNG.
- Added support for indexed PNG's (PNG-8) that can have an optional transparency.

Signed-off-by: Carlos Sobrinho <carlos.sobrinho@motain.de>
- Added the Gradle and .settings folder to the .gitignore list.

Signed-off-by: Carlos Sobrinho <carlos.sobrinho@motain.de>
Remove ternary from logic to get compress format
Increase the potential buffer size in Downsampler
updated readme
Add docs directory to .gitignore
Don't throw an exception if a tag is replaced