Added an extra hrf kernel, similar to the one used in SPM, a mixture of Gammas.

git-svn-id: https://repo.thevirtualbrain.org/svn/tvb/trunk/scientific_library@5079 1c0e02f0-7929-43c0-8fb3-3293bf43b0d1
Adjusted par values for two hrf equations

git-svn-id: https://repo.thevirtualbrain.org/svn/tvb/trunk/scientific_library@5081 1c0e02f0-7929-43c0-8fb3-3293bf43b0d1
Updating Tutorial for BOLD

git-svn-id: https://repo.thevirtualbrain.org/svn/tvb/trunk/scientific_library@5082 1c0e02f0-7929-43c0-8fb3-3293bf43b0d1
Updates the length of the hrf and memory guesstimate for bold in simulator.py

git-svn-id: https://repo.thevirtualbrain.org/svn/tvb/trunk/scientific_library@5083 1c0e02f0-7929-43c0-8fb3-3293bf43b0d1