- avoid `cmd /C dnvm.cmd ...` because `cmd` does not report `.cmd` script exit code correctly
- change both `_dnu.shade` and `_k.shade` though `_k.shade` is more-often an issue
- @moozzyk reported problem in [discussion](https://github.com/aspnet/Universe/pull/299#discussion-diff-41954492) of PR #299
- #290
- remove workaround for aspnet/dnx#2566; not needed if building with CLR or Mono
- install Core CLR DNX in `build.sh`
- must be applied in all repos using Travis before this PR goes in
- add `Dnu()` and `Dnx()` macros
- remove `K()` macro from `_k-test.shade`; use `Dnx()` instead
- incorporate per-repo changes not yet applied to Universe templates
- use newer `NuGet.exe`
- Universe itself does not need the Korebuild package or `dnvm`
Changes partially revert 618a73b e.g. always start build with CLR or Mono DNX
nits:
- reduced DNX switches and `dnvm` calls in `build.cmd`
- base NuGet skip decision on _both_ KoreBuild and Sake's installation status
- make `Quiet` variable work more reliably; small changes often led to compilation problems
- requires a small change in DNX repo at the same time
- remove some trailing whitespace and tabs
- add a bit more description to `_k.shade`
Doug Bunting