add chsh command

chsh (an abbreviation of "change shell") is a command on Unix-like operating systems that is used to change a login shell.

ref: http://en.wikipedia.org/wiki/Chsh
Added new keywords from PHP 5.5 to PHP brush
Merge pull request #256 from elazar/master

Added new keywords from PHP 5.5 to PHP brush
Changes build system to use grunt.
Fixes up tests.
Updates README.
Merge pull request #244 from payliu/patch-1

Adds `chsh` command to bash brush.
Adds missing node-sass dependency.
Merge branch 'master' of github.com:alexgorbatchev/SyntaxHighlighter
Fixes build on windows and makes it simpler.
Updates MIT license file with the right name... finally :)
Fixes copyright date in the HTML about dialog.
Cleans up build system further.
Fixes windows build issue with new lines.
uodate the code