add MathLib/Nonlinear in CMakeLists.txt
- move VecNormType to LinAlgEnums.h
- extend norm functions
add Picard class
add tests for Picard
remove unnecessary include
document private members
rename template parameter names and add documententation
make file ending consistent with other files
fixed indentation
condition-files can now be read from and written to ogs-project-files
adjusted cnd-interface test
Merge pull request #426 from rinkk/CndToProject

Reading and writing condition-files to OGS projects
correct handling of LineEdits and PushButtons in Condition Setup Dialogue
added missing method for pyramid-elements to edge-ratio metric
fixed handling of filename for writing condition-files in gui
Merge pull request #189 from norihiro-w/add-Picard

Picard nonlinear solver