Add 2D elasticity notebook example

Address issue #68

Add first draft of elasticity notebook. Still need to work on the api for random microstructures for elasticity for more than 2 phases. Need to know what units Sfepy expects the Young's modulus to have.
Add numpy fftshift and numpy pad to resize_coeff

Address issue #67

Add fftshift and pad to the method resize_coeff to do the padding of
the influence coefficients in a more canonical way. The constant
valued influence coefficients still need to be addressed.
Fix constant valued coefficients and pad placement

Address issue #67

Fix constant valued coefficients to scale properly when zero padding
by increasing the size of all dimensions by an integer value. Still
need to look at scaling in 3D and for any shape.

The zero padded influence coefficients were not centered
correctly. Fix placement and doctest for resize_coeff.
Fix MKS elasticity test

Fix MKS elasticity by removing the boundary cell where the assumption
of periodic boundary conditions is not valid. The tolerance was also
increased slightly.
Fix Boundary Conditions and resize_coeff

Fix issue #67

Fix the boundary conditions for the ElasticFEModel to have the
macroscopic strain value for any size microstructure. The previous
boundary conditions were incorrect and were creating an error with
re-sized influence coefficients.

Fix zero padding of the constant coefficients. For the constant valued
influence coefficients, the k0 value stays the same regardless of the
re-sizing.
Fix doctest verbose issue

Fix doctest by including directives to ignore the output from sfepy
generated while computing the strain field.
Add nosetests for resize_coeff method

Address issue #67

Add nosetests for resize_coeff to ensure that the method doesn't break
when added functionality to the package.
Merge branch 'issue52-docs'

Address issue #52
Merge branch 'master' into issue67-resizeCoeff
Merge branch 'issue67-resizeCoeff'

Fix #67
Add HTML titles, logos and icons.

Address #52.

The colors for the logo are #58b91a and #f1d71d
Merge branch 'master' into elasticity-notebook
Add re-sized coefficients to 2D elasticity notebook

Address issue #68

Add re-sized coefficients to 2D elasticity notebook to demonstrate how
to use the method resize_coeff.
Switch to Bootstrap theme

Address #52

Bootstap theme seems much nicer.

 * remove search box

 * switch to sphinx_bootstrap theme

 * using contents file instead of index

 * reduced size of logo

 * remove copyright
Add MKS equation derivation

Address issue #65

Add MKS equation derivation to show where the MKS equation comes from.
Move master file back to index.rst

Address #52

PyMKS icon can't point at anything other than the master file. Include
the introductory notebook in the master file.
Clean up README.md for webpages.

Address #52

Clean up from page by merging README and IPython notebook in
index.rst.
Correct typos in the MKS derivation.

Address issue #65

Correct typos in the MKS derivation
Clean up intro for front page

Address #52
Merge branch 'elasticity-notebook'

Fix #68, fix #65