Added experimental support for compressible/incompressible material in tet21stokes.
Included tinyxml as an external library, which can be built using cmake. Tested compilation on Windows XP under MinGW.
Added full bi-quadratic interpolation for quadrilaterals (9 nodes). Untested.
Added more latex output files to .gitignore.
Merge branch 'master' of https://github.com/Micket/oofem
Uncrustified some files.