Prepare for release 1.3

git-svn-id: https://repo.thevirtualbrain.org/svn/tvb/trunk/tvb_documentation@6814 1c0e02f0-7929-43c0-8fb3-3293bf43b0d1
Update Stimulus section in UserGuide (new screenshots, revive the text).

git-svn-id: https://repo.thevirtualbrain.org/svn/tvb/trunk/tvb_documentation@6822 1c0e02f0-7929-43c0-8fb3-3293bf43b0d1
TVB-1631: Organize handouts files in folders corresponding to the workshops they are presented in

git-svn-id: https://repo.thevirtualbrain.org/svn/tvb/trunk/tvb_documentation@6823 1c0e02f0-7929-43c0-8fb3-3293bf43b0d1
TVB-1631: Move files from node 01 to corresponding folder

git-svn-id: https://repo.thevirtualbrain.org/svn/tvb/trunk/tvb_documentation@6824 1c0e02f0-7929-43c0-8fb3-3293bf43b0d1
Document performance issues. More accurate release notes.

git-svn-id: https://repo.thevirtualbrain.org/svn/tvb/trunk/tvb_documentation@6827 1c0e02f0-7929-43c0-8fb3-3293bf43b0d1
Merge branch 'master' of https://github.com/the-virtual-brain/tvb-documentation