Possession and allowance on its and lets

- Its is the possessive one,
  it's the contraction
- Lets is an allowance for things,
  let's usually warms our introduction

Fixes #77
[customization] anyway typo.

Fixes #78
Update source/getting_started.textile

Light typo edits
[ubuntu-deploy] Must include spree assets within static assets block in nginx config
Shipping category impact on ship method.
Remove default_locale references from preferences guide
Fix broken link for coupons and discounts

Fixes #81
Update guide for deployment service to require proper Linux distro (Ubuntu 12.04 LTS).

There were discrepancies between the guide and deployment service page; this commit simply updates the outdated text.

Fixes #82
Start of 2.0.0 release notes
no need to precompile assets any more
Remove section about Spree analytics setup from getting started guide
Fix typo error where 'msygit' should be 'msysgit'
Typo in in_taxons method

Fixes #85
[preferences guide] added 1 sentence about where Spree::Config comes
from.
Link to Deface's new home.
Add spree conf thin banner.
Remove spree conf thin banner from layout
Update deploying_on_ubuntu.textile

Update set :deploy_to to reference application not application_name
Update config/unicorn.rb to be consistent

This commit updates the naming of the pid in config/unicorn.rb to be
consistent with the pid naming that comes later in the config/deploy.rb
file.