Set the environment variables in a separate sourced script

Sourcing the GramSchmidt.sh script just so the environment variables can be
correctly set when the 'setenv' argument is used was becoming cumbersome when
writing functionality for other arguments. Creating a separate script for
setting the environment variables make the GramSchmidt.sh script much cleaner.

File: Build/GramSchmidt.sh
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- Removed the 'setenv' argument section
- Replaced all "return" commands with "exit" and cleaned up the error handling
- Fixed the 'release' section to force the 'git archive' command to include all
  files from PROJ_ROOT_PATH instead of the current path

File: Build/setenv.sh
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- Copied the 'setenv' code from the GramSchmidt.sh script