Snipmate description updated

Scrooloose snippets were replaced with honza/vim-snippets.
Snipmate's version notice removed

Another snipmate's fork (garbas/vim-snipmate) is used now. The notice is
obsolete now.
Merge pull request #465 from vdmgolub/snipmate_docs_update

Snipmate docs update
zsh: clean-up aliases
vim: fix yankring file location
vim: add latex-suite, graphviz
vim: remove ruby plugins