Remove Rspec plugin & mappings

Since I'm mostly running Rspec in Tmux split anyways
Remove close fold mapping

Because it conflicts with other mappings and standard mapping is short
enough
Remap and make faster copy/cut text without linebreaks
Remove :tabclose mapping 'cause it slows down new tab open
Disable autocompletion (kinda annoying)
Remap Files dialogs to use leader instead of Ctrl

Use of Ctrl is anti-pattern in Vim