Turned logging off again in unit tests

Huge volume of logs makes it less useful, plus it will kill the build
server quickly (limited disk space etc.).

Calibrate/redo npgsql logging before reenabling this (#279)
Revert "Hacked nuget.targets to work on Windows/mono"

This reverts commit bf28c73be7d3327f0c9c5fe21e2abcc6441fcaf9.

See #137
[MonoIgnore] on 2 tests

Fixes #288

Failures are a mono issue, see https://github.com/mono/mono/pull/1172
Merge branch 'master' of https://github.com/npgsql/Npgsql into operator-precedence-ef
Ignore failing EF tests on mono (probably due to bug in mono).