Consolidate Graph Builders

[clue]

We currently have several classes that are concerned with creating / building graphs from certain parameters or input graphs:

• Algorithm\ResidualGraph
• Algorithm\TransposeGraph
• Loader\CompleteGraph
• Future ComplementGraph (see Add complement Graph algorithm / builder #60)
• Possibly some others

IMHO both Algorithm and Loader are bad descriptions and do not quite describe their responsibility. As a first step, I'd vote for grouping these in a new Builder (or similar) namespace. In the future we should work out a decent API (interface).

Refs #120.

[clue]

The name "Builder" will probably be confusing with regards to the builder pattern.

Ticket #119 suggests we should stabilize the core graph library and split off optional sub-namespaces. The suggested Builder namespace would probably be one such candidate, and as such we should probably avoid introducting yet another namespace in the first place.

Instead, I'd suggest we should move the CompleteGraph into the Algorithm namespace. This will obsolete this issue.

[clue]

The name "Builder" will probably be confusing with regards to the builder pattern.

Marking this ticket as invalid.

Instead, I'd suggest we should move the CompleteGraph into the Algorithm namespace. This will obsolete this issue.

Loaders will be split off via #117, algorithms will be split off via #119.
As such, this is blocked until both issues have been resolved.
I've filed two new tickets that keep track of this state.