Cache avatars by MD5 of URL instead of base64
Ensure old cached folder is always deleted
Prepare 1.7.1 release
Remove typo in integration-tests pom verison
Fix a message

Closes #395
Update Japanese translation

Closes #398
Update german translation

Closes #401
Delete dead method and unused constructor.
Annotate overridden methods.

Closes #394
Small refactorings of HtmlUtils.java

Reduce scope of some variables, add @Override annotations, etc.
Closes #403
Add empty lines between constant variables
Remove unused ci profile that used deleted plugin
Set release to true in release profile
Prepare 1.7.2 release
Bump versionCode for 1.7.2 release
Prepare 1.7.3 release
Fix typo in Greek translation.

Closes #424
Update slovak locale

Closes #431
source-editor.js: add missing semicolon.
Update README.md.

Add title to the Google play image and use code syntax where applicable.