Select text whit shift and (un)indent whit tab

Allows the user select text by pressing shift and maps Tab to indent command + Shift-Tab to unindent command in vim. 
Also would be great to have this plugin into subvim to improve NERDTree Experience (https://github.com/jistr/vim-nerdtree-tabs) and to set by default 
let g:nerdtree_tabs_open_on_gui_startup to 1 since it is easier for newcomers to have the file tree opened on startup found this by my own experience, im not a vim power user but
a SublimeText user trying to switch to vim.

Good job