Better experience of failing package installation

[MichaelChirico]

I have some C++ lib issue that was hidden by quiet=TRUE, I only experienced this as:

Error in file(con, "r") : cannot open the connection
In addition: Warning message:
In file(con, "r") :
  cannot open file '/tmp/RtmpryiHR0/R_LIBS25202924885e/TestCompiled/R/TestCompiled': No such file or directory

Not very helpful.

[jimhester]

I think we should probably make this an error rather than a warning. I don't know of any cases where a non-zero return from package installation would still be workable.

[jimhester]

Thanks, appreciate the contribution!