Fixed a wrong index.
A minimal comment
Merge pull request #14 from sissa/fix_docs

Fixed a wrong index.
Merge pull request #17 from GivAlz/fix_docs

basis_span comments and cell_span
added a comment
Merge pull request #15 from nicola-giuliani/fix_docs

added a comment
Added short documentation for "evaluate" function
Fixed error in documentation
Switched from tabs to spaces
Fixed variables names

Conflicts:
	interfaces/vector_space.py