remove methods of KeyValueFormat that are deprecated since 2.7
Add missing @Nullable to KeyValueFormat
SONAR-5768 API: org.sonar.api.utils.KeyValueFormat does not support escaping of values
Merge remote-tracking branch 'remotes/origin/branch-4.5'

Conflicts:
	sonar-plugin-api/src/main/java/org/sonar/api/utils/KeyValueFormat.java