Removing NerdTree plugin

I never use it, and vim has builtin functionality to browse directories.
Setting default :set list characters
Adding Command-T plugin for file search

This is the raw checkout version, with nothing compiled yet. This is so
we can avoid committing build output.
Fixing conflicting key-mappings between the tasklist and Command-T plugins
Updating listchars and soft line-wrapping
Adding custom version of color-scheme

Minor tweak for colors of listchars, so that they'll be easier to see.
Adding notes about linenumbers settings

I'm not actually changing the settings here, but making notes so it's
easier to change later if need be.
Updating tags configuration option and adding Ctrl-F12

- Vim will search up directories looking for a tags file now. Will stop
  at the user's home directory.
- Ctrl-F12 will build a tags file from the current directory.