Rename CLI analyze command to suggest

[osma]

I'd like to rename the analyze CLI command (and also the REST method, but that's a separate issue) into suggest, following the example of the Maui Server API which has a similar method.

I realize this may break existing uses, but hey, Annif is still in 0.x versions where breakage is expected, and if you're going to do it it's better to do this early. I've never been very happy with the analyze command name, for example because it clashes with the concept of Analyzers which are just the first part of the operation.

After the change the wiki documentation needs to be updated as well.

[osma]

The analyzedir command could be renamed to index in the same go.

Within the codebase, all methods named like analyze could be renamed suggest.

[osma]

AnalysisHit and AnalysisResult need to be renamed as well for consistency. SubjectSuggestion and SuggestionResult maybe?