Remove c++ internal headers from install if possible

[dankamongmen]

Hey @grendello my man, do we need to be installing internal/Helpers.hh, or the three headers prefixed with _? If so, no worries. If not, let me know and I can pull them out of the install, or you can. Thanks!

-rw-r--r-- root/root       751 2020-11-22 05:22 ./usr/include/ncpp/Utilities.hh
-rw-r--r-- root/root      3505 2020-11-22 05:22 ./usr/include/ncpp/Visual.hh
-rw-r--r-- root/root       855 2020-11-22 05:22 ./usr/include/ncpp/Widget.hh
-rw-r--r-- root/root      1164 2020-11-22 05:22 ./usr/include/ncpp/_exceptions.hh
-rw-r--r-- root/root      2060 2020-11-22 05:22 ./usr/include/ncpp/_flag_enum_operator_helpers.hh
-rw-r--r-- root/root       332 2020-11-22 05:22 ./usr/include/ncpp/_helpers.hh
drwxr-xr-x root/root         0 2020-11-22 05:23 ./usr/include/ncpp/internal/
-rw-r--r-- root/root      1002 2020-11-22 05:22 ./usr/include/ncpp/internal/Helpers.hh
-rw-r--r-- root/root       123 2020-11-22 05:22 ./usr/include/ncpp/ncpp.hh

[grendello]

They need to be installed, yes. They are "internal" in the sense that they should not be included directly by the user code as they contain "magic" stuff used by other headers.

[dankamongmen]

Shut her down, boys! Thanks a lot for the explanation (and not making me go look into it).