E3-341: Improve the shell prompt to display e3 info

When user run setE3Env.bash script, the script will setup e3 environment for the shell so that the user can work in a proper e3 environment. User usually work with several different version of e3 at the same time and might switch between them. This make it very easier for an user to lost tracking of which version of e3 they are working right now. Another problem is that, if the script is not properly sourced, the e3 environment variables that the script prints out might not be the same version which reside in the shell's environment if user switch versions. This change add e3 version information to the shell's prompt string, so that user can easterly see which version of e3 currently they are using. And also, additional check is imposed to make sure that the script is properly sourced and the print out of the e3 environment information reflects the corresponding environment variables in the shell(Now, and the shell prompt string).