Write Tecplot header based on the dimension of the actual elements in
the Mesh, rather than mesh.mesh_dimension().
Factor out logical element dimension checking into a separate function
so it can be used in both the ASCII and binary writers.
Use elem_dimension instead of Mesh dimension in the binary Tecplot writer.
Add ability to search for X11 header files in different locations,
and pass this path down to the TECIO Makefile.
Adding t = "T n" to the header in the ASCII Tecpot files seems to be
enough to allow Tecplot to figure out how to animate Zones by clicking
through the Data -> Edit Time Strands dialog.
Merge pull request #219 from libMesh/tecplot

Write Tecplot header based on the dimension of the actual elements