set LINEMAN_ENV based on CLI command.

This is only set internally and cannot be overridden by the user for
the spec, spec-ci, or build commands
Upgrade fetcher to support append/prepend
Support programmatic async calls.
Grunt task for lineman fetch CLI action.

Usage: 
$ lineman grunt fetch:facebook-connect-api-all:google-analytics:twitter-widgets-api
0.33.0
Sticks the overrides in a way that supports clean.
0.33.1
git ssh fails when no cert exists

Builds fail on heroku b/c no SSH cert is sent to github. HTTPS should 
work, however.
0.33.2
upgrade grunt-watch-nospawn
0.33.3
Added live reload connect to express.
clean up livereload middleware config

changes where options are searched for to top-level "livereload" to 
facilitate easy sharing of config with the grunt-watch-nospawn task.
upgrade grunt-watch-nospawn
give example livereload config snippet /archetype
0.33.4
upgrade grunt-watch-nospawn
0.33.5
Allow users to specify their watch module

Lineman defaults don't change, but users can define:

```
watch: {
  options: {
    module: "grunt-contrib-watch"
  }
}
```

And install `npm i --save-dev grunt-contrib-watch` locally, and that 
one will be used for the watch task.

The goal is to give a path for people who outgrow our 
grunt-watch-nospawn for feature's or project size, and are willing to 
sacrifice its modest speed advantage without creating a lot of friction.
0.34.0