Prevent error when file doesn't exist
Put powerline in its on bootstrap

I didn't realise initally that it's used beyond vim.
Remove ambiguous message on vim bootstrap

On first run, when the vimrc doesn't exist, if you tried to remove it,
this would produce a 'file does not exist' message, which left it
ambiguous as to whether or not the bootstrapping had failed. The seeming
duplication of the link command is also necessary for that same reason,
because it produces console output that leaves it uncertain as to
whether or not bootstrapping succeeded.
Remove dot in profile directory reference
Fix vim bootstrapping

It turns out you can't check for the existence of a hard linked file. A
better solution is just using -f on the rm and ln commands, which
supresses the potentially ambiguous messages.
Install vim-json