Merge pull request #76 from chrispbradley/master

Fixes for finite elasticity to use a geometric general dependent field
Merge pull request #77 from chrispbradley/master

Fixes to the Analytic Laplace test to get it working.
remove superfluous example files in Extracellular Bidomain Poisson
remove superfluous example files in Extracellular Bidomain Poisson - remaining file
add new example for extracellular bidomain equation including inputdata
Merge pull request #78 from mylenamordhorst/master

updated example for extracellular bidomain (poisson) equation