Update Submodules

Brings the following submodules up to master:

bundle/ctrlp
bundle/endwise
bundle/fugitive
bundle/nerdtree
bundle/rails
bundle/repeat
bundle/surround
bundle/tlib
bundle/unimpaired

Removes the following submodules that are no longer used:

bundle/LaTeX-Box
bundle/tmux-syntax
bundle/tslime.vim