Clean up

[Rombur]

Here is a list of things that we can do to improve the code:

• Replace class by typename in template parameter (right now we are not using any thing consistently. Example: VectorType is sometimes a class sometimes a typename)
• Put const on the right
• Rename adapters_dealii to dealii_adapaters (consistency with dealii_operator)
• Use child property tree
• More tests: including a test with variable number of eigenvectors per agglomerate.
• Reorder public, protected, and private
• evaluate for the GlobalOperator requires to copy the system sparse matrix. This is a pretty expensive operation. Instead, we should just ask for a shared pointer
• Add clang-tidy to jenkins
• Fix warnings