add analyzer storage and report infrastructure

+analyzer storage backends (infinite, packet count, time span)
+tests for the backends
+window size analyzer
+threads for reporting (sigusr1) and status output (sigusr2)
+locking
+cleanup for flow table, analyzer data, flows at exit
+fixed some warnings/bugs shown by clang

...unified analyser/analyzer mess to analyzer in some places
rough overview of the used data structures of the packet processor
fix warning

enum is unsigned...