Clean up code

[dstenger]

Code and configuration of teamengine Maven project shall be scanned for obsolete content and refactored if necessary.

[dstenger]

Candidates to be cleaned up:

• Maven profiles
• Maven module teamengine-virtualization
• Listed developers in pom files
• Shell scripts
• Outdated documentation

[dstenger]

Branch: https://github.com/opengeospatial/teamengine/tree/cleanUp-591

[dstenger]

Issues were detected by IntelliJ IDEA and marked as warning:

• Remove redundant conversions to string
• Simplify boolean expressions
• Remove unused imports

[dstenger]

Issues were detected by IntelliJ IDEA and marked as warning:

• Simplify call for file seperator
• Simplify conditional expressions
• Remove obsolete local variables
• Use class instead of instance for static method calls
• Replace explicit type with <>
• Use method sort of List
• Remove obsolete plus
• Refactor Arrays.asList() with too few arguments
• Remove obsolete Collection.addAll() calls
• Use String.isEmpty()
• Use String isEmpty() method
• Remove obsolete semicolons
• Remove modifier public from interfaces
• Use StandardCharsets

[dstenger]

Follow up issue was created: #613