Merge pull request #681 from runasand/develop

Include changes suggested by @ageis
Merge pull request #687 from runasand/develop

Updated user manual for 0.3 (todo: screenshots)
Split and merge full_install.md into separate, related docs

Also updates instructions, formatting, and cleans up whitespace.
Update grsec kernel build docs to latest built kernel

* Updates the docs for Ubuntu Trusty (14.04.1) because we switched to it for SecureDrop 0.3
* Updates versions of grsecurity patch and linux kernel to the versions used in the most recent successful build of the grsecurity kernel
* Fixes some formatting and trailing whitespace issues