Update Boost to 1.55
Update gcc to 4.8
Follow advised .travis.yml format

http://docs.travis-ci.com/user/build-configuration/#Build-Lifecycle
http://docs.travis-ci.com/user/installing-dependencies/#Installing-Ubuntu-packages
Adding command class
Use tokeniser interface
Avoid warning about not returning a value
Avoid trigraphs in string literals
Specify lambda return type
Escape trigraphs in string literals
Remove warnings on Windows
Build WinEditLine together with Metashell
Replace Boost elements with C++11 ones
Increase warning level
Stop tokenisation at first error
Merge pull request #5 from r0mai/3pp-update

3pp update
Merge remote-tracking branch 'sabel83/master'

Conflicts:
	.travis.yml
	app/readline_shell.cpp
	include/metashell/pragma_handler_map.hpp
Eliminate unused variable warnings