Add support for GT.M on Centos/RHEL

There are some slight changes needed for GT.M and EWD.js to work on RHEL
using the same scripts which include a different prefrence for .profile
or .bash_profile an the linker configuration defaults.

Add checks for platform using variable defined in autoInstaller.sh to
ensure any platform specific changes are only executed on the right
platform.

Change the source lines for nvm to run the nvm script directly without
sourcing .profile/.bash_profile.

Change-Id: I67e3421d17a12a7f34a99a586f3bd130ef3a4f35