Always print stack traces when showing errors
- We can't tell where errors occured so always show the stack trace
since it's better than hiding it.

#539
Reacting to System.IO.FileSystem package version change
Reacting to System.IO.FileSystem package version change
Reacting to System.IO.FileSystem package version change
Make mono run as .NET 4.5.1
- Turns out mono's 4.5 profile (for the versions of mono we support)
is actually compatible with .NET 4.5.1.
- Fix problem with compiling against reference assemblies
that were not resolved via dependency resolution.

#511
#374
Removed too much code in a previous commit
- Fixed regression
Allow no-throw behavior when command-line parser sees an unexpected option
Fix "kpm restore" with global.json

- Use the global.json as the single source of facts. No project.json is
  needed.
- Strictly restore the packages in global.json. No more no less.
- Restore exact version of a package when restoring with gloabl.json
added support for async command line
exception test
Check for correct exception
fixed test