Cleanup4

[Photon-GitHub]

Another cleanup pull request :)

Main features:

• Replaced a string equalsIgnoreCase chain with a switch lookup
• Made some cache lookups faster by querying only once
• Replaced the weird command init in the main class and removed its private enum
• Faster RangeParser with BitSet (maybe a test for this might be a good idea?)
• Replaced some manual mappings with streams
• Use ImmutableSet for the report filter
• Replace old BiFunction from pre-java 8 times with the new java equivalent.