Adding solver monitor to the navier-stokes example.

Implementing tnl-diff.

Changing indexing in grids.

Adding tnl-view tool.

Adding directory legacy for old code.

Renaming tnlArray to tnlMultiArray.

Finishing new template interface for GMRES.

Adding unit tests for tnlString, tnlObject and tnlArrayManager.

Adding new class tnlArrayManager for managing arrays - allocation/deallocation, load and save functions etc.
tnlVector is derived from tnlArrayManager.

There is gap of missing commits.