Build doesn't install examples

[Scott Baden]

It's probably a good idea to include the example codes from the PG in the build. Otherwise , anyone who uses the module system will have to download the upcxx tarball.

[Paul Hargrove]

At today's meeting we agreed this is valuable, but too late to do safely for Mar 2018.
Both the PG examples and the tests should be in the "share" directory of the install.
So, we will defer to the next release (perhaps a beta before Sep).

[Dan Bonachea]

This issue was triaged at the 2018-06-13 Pagoda meeting and assigned a new milestone/priority.

Steve noted the examples are currently incorporated into a framework that doesn’t look like the PG version, so installing the working source code may be confusing to users.

[Dan Bonachea]

This has been added to the UPC++ Spack packaging in https://github.com/spack/spack/pull/23832

The examples are also now included in the home directory of our Docker containers.

Anyone installing manually from source already has a copy of the examples (and they are of course always easy to retrieve from upcxx.lbl.gov).