* add checks for famANDassembly visibility

fixes https://github.com/Microsoft/visualfsharp/issues/1373

* add unit tests for FamAndAssembly / FamOrAssembly

* disable failing test

* adapt ut error message for error message rework

* add issue link to disabled unit test

* align and replace all tabs with whitespace (maybe build failure is related to tabs? I'm probably paranoid ....)

* -a => --target:library

* fix assembly

* fix FamAndAssembly

* manually modify accessibilities in AccessibilityTests.dll

* Revert "-a => --target:library"

This reverts commit 33af6458fc2839511e7b110b4b0c3922ff95fa4e.