Implements first simple WatchDogStatistics Window

Refs #15
Implements WatchDogWindow with Statistics

Refs #15
Modifies order and Changes Text to be more clear

It could happen that the current session has a greater value than all sessions
combined, and that would have been unclear. Not sure whether a combined
counter would actually make more sense, but at least it's clear now what is
displayed.

Refs #15
Reverses order of % and absolute values (indicating that %s are indeed more
important than the absolute time)

Refs #15
Modifies Doc

Refs #15
Merge pull request #19 from TestRoots/createWatchDogPluginStatusPage

Create watch dog plugin status page