new device class + capacitor 2d template generator finished

now, off to updating the, e.g., nin2d example to identify required
viennamini changes with the new device class
working on 'new' simulator: work in progress ..

switching to new device class and also considering different simualtion scenarios,
like capacitor, resistor, ... and the thus required modeling
fixed compilation errors introduced at last commit: nin2d dev compiles
added io::read_vtk method
provided 'scale' wrapper capable of handling viennamini's device
revisited nin2d example

now off to fill the simulator functor ...
nin2d: simplified includes
working on new simulator interface

config/storage/device/material_library reside in the simulator beginning from now.
no simulation functionality right now

-> currently working on material_library class
changed include file in material_library -. compiles again
quicksafe: switching to new approach for using external viennaprojects

using 1. externalproject_add and git
2. env variables

-> just started working on it, nothing compiles
added Find*/Get* cmake modules

@ Find*: uses the environment variables to find and build the vienna libraries
@ Get*: uses CMake's externalproject_add-git option to automatically download and compilie the ViennaLibraries
  -> only the git download is implemented right now, still need to set the includes/library paths
added ViennaFVM cmake find/get modules + fixed include paths of cmake modules

nin2d example compiles (though simulator is still empty)
working on viennamini::material_library

dummy ready, already imports files according to their fileending
automatically via viennamaterials.
nin2d example builds and links iwth the new cmake build system
removed old readme file
added cmake dependency: libviennamaterials.a/.so -> libviennamini.a/.so

now parallel builds are supported, e.g., -j4
cmake now configures device_collection.hpp.in

device_collection.hpp provides the inlined
viennamini::device_collection_path() function, providing the path to the
devices on various platforms
device class can now read and write netgen files
device class can now detect interfaces: contact-semicon-oxide
quicksafe: working on outsourcing the poisson-dd part.

not sure if this is the proper way to do it. need to investigate new
viennafvm, and storage approach to get an idea how to handle
the input and output data of the viennafvm simulation
quicksafe: added 'problem' hierarchy, working on poisson-dd-np

simulation for nin2d exectutes but doesn't converge atm (probably forgot some setup routine)

currently dealing with some significant troubles with the parameterized pde_solver class,
due to compile-time meshtype dependency