Change version to 0.3.0-SNAPSHOT.
Add sharpen filter.
Add strength parameter.
Add documentation.
Merge branch 'feature-sharpen-filter'
Add emboss filter.
Add option to define emboss strength.
Change matrices central cell value.
Extract matrix scaling to helper and add unit tests.
Change matrices central value back to old one.
Fix scaling algorithm to not scale central matrix cell.
Add documentation.
Merge branch 'feature-emboss-filter'