More accurate ranking algorithm

[DavidBelicza]

In case 1, the icons - tray and extension - gnome phrases got 0.5 weight, but it's clearly noticeable that extension - gnome is a more important phrase than icons - tray. The two phrase's occurrence is equal but the gnome word itself has more hit than icon or tray words. Follow this logic, the extension - gnome weight should be > 0.5 and < 1.

But this logic should not make that side effect what happens in case 2, all phrases become important what contains the word gnome.

Case 1 and case 2 are correct, so they shouldn't be modified but a new algorithm is required what implement the above logic. It should be a new, third Algorithm interface implementation: SupervisedAlgorithm or ComparatorAlgorithm.

Case 1, FindPhrases method result from ranked text by AlgorithmDefault

• Phrase: gnome - shell, Occurrence: 5, Weight: 1
• Phrase: icons - tray, Occurrence: 3, Weight: 0.5
• Phrase: extension - gnome, Occurrence: 3, Weight: 0.5
• Phrase: dock - dash, Occurrence: 2, Weight: 0.25

Case 2, FindPhrases method result from ranked text by AlgorithmMixed

• Phrase: gnome - shell, Occurrence: 5, Weight: 1
• Phrase: gnome - caffeine, Occurrence: 2, Weight: 0.8
• Phrase: gnome - takes, Occurrence: 1, Weight: 0.73333335
• Phrase: gnome - commonly, Occurrence: 1, Weight: 0.73333335

[DavidBelicza]

Done in PR #5 New algorithm name is ChainAlgorithm and MixedAlgorithm has been removed.