Update vim-improvements.vundle

This removes a redundant Bundle that already appears on line 9. This was throwing warnings for me whenever I started macvim.
Merge pull request #470 from martco/patch-1

Update vim-improvements.vundle
Decided disabling arrow keys was hurting new people too much
Adding symlinks for user config files so that they can be synced with GitHub as well
Adding symlink for .zsh.after
Updating the URL reflect forked repo
Adding -g flag to escape-time setting
Fixing bug in clear-screen remapping
Adding matplotlibrc to tracked files, requires another symlink
Merge branch 'master' of github.com:justmytwospence/dotfiles

* 'master' of github.com:justmytwospence/dotfiles:
  Adding matplotlibrc to tracked files, requires another symlink
  Fixing bug in clear-screen remapping
  Adding -g flag to escape-time setting
  Updating the URL reflect forked repo
  Adding symlink for .zsh.after
  Adding symlinks for user config files so that they can be synced with GitHub as well
  Adding symlinks for user config files so that they can be synced with GitHub as well

Merging with the upstream fix for vundle redundancy.