marks: added mark functions to .bashrc

from http://jeroenjanssens.com/2013/08/16/quickly-navigate-your-filesystem-from-the-command-line.html
removed cdcr shortcut commands, cause that's a mark now
removed duplicated rvm/bin export
rebase: fixed whitespace of mark funcs
huyng/bashmarks instead of marks

using https://github.com/huyng/bashmarks instead of marks, because
the commands are shorter and auto-completion works
removed rails aliases