v5.2.4-snapshot.7-g037cc82

Graph

• Linux - add Network CPU processing (softirq)
• Linux - remove "Memory Pages" output created by "sar -R"

BUILD

• update dependencies - logging (slf4j,log4j), junit
• update Gradle - Gradle6 (support Java14); Gradle Plugin to support Gradle6, gradle checksum
• adapt Travis build process - build config validation, build with Java openjdk 8,11,14 and 15 (EarlyAccess)