Removing vim-rails

The only feature being used was RSView for creating new files. It can be
easily replaced with :sp %:p:h
Swarp mouse pointer to the mid-top

Issues seen with placing mouse pointer in the right section. With two
vertically split windows, the focus would occasionally move to the
window containing the mouse pointer.
Bring focus back to current window after moving mouse pointer
Removing unused vim plugins
Grouping related vim scripts