Merge pull request #5 from sebasguts/master

Fixed dependencies in makefile.
GradedHom -> CombinatorialHom

GradedHom conflicted with the declaration in GradedModules

\#I  method installed for GradedHom matches more than one declaration
Now based on ChernCharacter: HilbertPolynomial, ChernPolynomial
Merge branch 'master' of github.com:homalg-project/CombinatoricsForHomalg
fixed Subtitle/LongTitle
New Function: Head
Fixed: Dual( of a free module ), CombinatorialHom, Hom
Merge pull request #6 from sebastianpos/master

Bug Fixes, Simplifications, Head as a New Function
renamed variable_for__Hilbert_series -> variable_for_Hilbert_series
started temporary support for matroids

. TuttePolynomial
. CharacteristicPolynomial
. PoincarePolynomial
updated bib
coding style
declared and installed LeadingCoefficientOfPoincarePolynomial
use TuttePolynomial from 2013-10-19

outsourced VariableForCharacteristicPolynomial to
alcove with the name IndeterminateOfCharacteristicPolynomial
added missing function_label
outsourced remaining code for matroids to alcove 2013-10-24
New doc standard