Improve Bloom.proj

This change allows to use Bloom.proj on a developer machine.
Allow to run unit tests on developer machine

This allows to run unit tests on Windows and Linux.
Merge pull request #201 from ermshiperete/AddTestTarget

Improve Bloom.proj
Debugging TC builds
Debugging TC build

For some reason TC doesn't report number of tests anymore with my
changed project.
Another attempt to get TC to display test results
Fix typo
Trying to fix Linux TC build
Another attempt to fix Linux TC build
Fix Linux TC build

Looks like teamcity_dotnet_nunitlauncher_msbuild_task variable
isn't set correctly when running on Linux, so we have to get
the NUnitTeamCity task a different way.
Fix Linux TC build

For some strange reason the variable agent_home_dir seems to be
empty when run on Linux. Same thing works in Palaso!? Anyway,
trying with teamcity_agent_home_dir.