Script support in vsprog

options for script:

-q option:
    This option is used to enable quiet mode, in which only result will be outputted, script commands will not be outputted.

-V option:
    This option is used to define one command to execute, the command should be between " and " if there is space in the command.

run script:
    There are 3 ways to run script.
    1. use -V option to run a single script. Use -V "run file.vts" to run a script file.
    2. use -V shell to enter into shell mode, the user can input scripts to run manually.
    3. append scripts files at the end of the command line. Vsprog will run them one by one.

Comment:
    If the first non-space character of a line is '#', this line is comment line and will not be executed.

Hide current command:
    If the first non-space character of a line is '@', the command after '@' is executed and the command will NOT be displayed. This is usually used with "quiet" command, to hide the "quiet" it self.