do_all_analysis.sh: Use settings_file.txt

Make the do_all_analysis.sh script more generic by putting
the settings into settings_file.txt. settings_file.txt is
then sourced to load the settings into the script.

The settings_file.txt contains MM settings as an example.
Later scripts will create this file or delete it. If the file is
missing then environmental settings can be passed in via
the command line.

Signed-off-by: Dean Jenkins <Dean_Jenkins@mentor.com>