Adds NERDTree vim plugin.
Adds alternate file vim plugin.
Adds tcomment vim plugin.
Adds powerline vim plugin.
Adds vimwiki vim plugin.
Adds autoclose vim plugin.
Migrates the rest of the old vimrc settings.
Updates bashrc.

Copies most of the settings from the default Ubuntu bashrc.
Ignore changes in vimwiki submodule.

The vimwiki plugin does not ignore doc/tags (generated) by default.
Fix issue where vim would try to loadview for nofile.

The error was caused by opening vim windows without a file (quickfix,
help, etc.).