lots of changes to make 14.04 possibke
Update bootstrap.sh

resolves https://github.com/sans-dfir/sift/issues/17
resolves https://github.com/sans-dfir/sift/issues/10
Merge branch '14.04' of github.com:sans-dfir/sift-bootstrap into 14.04

* '14.04' of github.com:sans-dfir/sift-bootstrap:
  Update bootstrap.sh
general cleanup, prepparing for 14.04 release
fixes https://github.com/sans-dfir/sift/issues/23
adding package rar and xdot, resolves https://github.com/sans-dfir/sift/issues/25
make sure to recursively checkout sift-files and submodules
resolves https://github.com/sans-dfir/sift/issues/24
support installing pip --pre distributions
resolves https://github.com/sans-dfir/sift/issues/33
resolves https://github.com/sans-dfir/sift/issues/32
remove bad package
resolves https://github.com/sans-dfir/sift/issues/29
Update README.md

resolves https://github.com/sans-dfir/sift/issues/34
fixing update script link
removing need for sift-base and sift-scripts packages
resolves #11, bitstring requirement for pe_carver
remove sift-scripts and fix 14.04 user favorites
general cleanup