Major update for `bfb-install` script: add remote rshim and netcat optimizations

[pgeng-nv]

This update is a major change to bfb-install script. Lines of code increased 4X from ~150 to ~750.

Major new functionalities:

• Added remote rshim so we can run BFB update remotely. Here "remote" means the RSHIM driver is running in a different processor other than the processor initiating bfb-install. Both processors will be in the same network, though they could be inside the same server enclosure. The remote rshim is invoked by using the new --method option if the argument is not the default server_rshim.
• Added a new option --method to support two types of optimizations: bmc_rshim_nc or bmc_rshim_ncpipe. Both are faster than bmc_rshim_scp, which is a repackaging of the current scp based process.

[pgeng-nv]

Will re-submit this pull request via a feature branch. Close it for now.