Added function to install latest release of a version - refs #176
Merge pull request #178 from chadrien/feature/latest-release

Added function to install latest release of a version - refs #176
Added tf as test suite for bash sripts
Added a Rakefile for tests automation
Added function do determine where phpbrew should be installed
Added a Guardfile for continuous testing
Better test for setting $HOME as prefix for standard user
Installer can detect operating system
Used better test methods
OSX dependencies are installed
Ubuntu deps are installed
Removed Debian from supported os list

Waiting to be sure of lsb_release value and to have the deps install
procedure
phpbrew bin is downloaded and installed
Renamed function
phpbrew is inited, and files are moved to global prefix if root user
Added a phpbrew system group and corresponding rights if sudo-ed

À la rvm
Added a post install function to set prefix lookup
Added messages display to describe each key step
Moved files to sh directory
add the release manager for php 5.6