Adding, changing and improving some key mappings

- Changing modifier key on splitted window navigation to "<Alt>" and setting only
  on gVim, because possible terminal's previous binding
- Select all text with "<Control-a>" in normal mode
- Key mapping to clear the search highlighting in insert mode using recursive behaviour
- "<Control-a>" goes to first non blank and "<Control-e>" goes to end
  line in insert mode, using recursive behaviour
- Better tab navigation: "<Control-h>" and "<Control-l>" jump to left or
  right tab in normal or insert modes
- Tab switching: "<Control-j>" and "<Control-k>" switches tab with
  previous or next tab in normal or insert modes
- "<Leader-t>" opens new tab in normal or insert mode
- "<Leader-n>" goes to normal mode
- Changing "i" to "<Insert>" to improve readability
Fix local conf loading

- Setting the right order: ~/.vimrc => ~/.vimrc.local or ~/.vimrc =>
  ~/.gvimrc => ~/.vimrc.local => ~/.gvimrc.local
Adding "EasyMotion" bundle
Adding "Emmet" bundle
Adding git stuff bundles

- Vim-Fugitive
- Gist-Vim
CtrlP Mixed Mode

- Search files in FS + MRU + Buffer. Useful when too many tabs are
  opened and a research simply jumps to tab already opened.