As a user I want many different presolver

[knoffi]

Presolver ideas:

• finding param with low value ( which is not in the ''hereafter'' )
• finding param with low grad ( which is not in the ''hereafter'' )
• finding param with high value ( will this converge faster? )
• find a low value between two params with high and opposite grads

[knoffi]

Useful for further presolvers:

Write a method that decides whether a point lies in the ''hereafter''. Ideas:

• go in the direction of its anti gradient until you find a high value
• go in the direction of its anti gradient until you find a param with gradient ''parallel'' to the previous antigradient

[knoffi]

Useful Idea:

A convexity penalty term could be useful for the non centered case ( like recent results in polygonReconstruct of file importantExamples.py show). Penalty term could be realized by:

• add a positive value if and only if it is no left oriented convex run