Fix nasty issue with makefiles in demo/
Fix demo after changes to TSSolve() in petsc-dev
Change install/uninstall makefile targes to user-type installs
Rename DA -> DMDA after discussion with Jed Brown

--HG--
rename : src/PETSc/DA.pyx => src/PETSc/DMDA.pyx
rename : src/PETSc/petscda.pxi => src/PETSc/petscdmda.pxi
rename : test/test_da.py => test/test_dmda.py