[Ktechlab-devel] Converting to Eigen - patch for revision, ver.1

[P Zoltan]

  Because the performance problems in my implementation, I'll suspend the  
Eigen integration. Also due SVN conflicts with trunk, I'm posting the  
current changes here :

http://sourceforge.net/userapps/trac/zoltan_padrah/ticket/4

  and reverting my local copy to svn trunk. Also see the notes in my wiki  
(linked there).

  There are a few possibilities to continue:

1. fix the current implementation; eigen can be useful for verification.

2. create an in-place LU solver. Allocating / releasing a matrix in each  
simulator (maybe more times / step) is highly inefficient.

3. use LU only when it's useful (only linear elements) and use other  
solver for the other cases (nonlinear elements, ...)

  I'll focus now on integrating the changes proposed by Santiago Gonzalez  
and bugfixing.