CLEANUP - Removed unused namespace references.
Merge pull request #273 from IAmAnubhavSaini/master

Remove some unused using statements in console.cs.
System.Numerics.Vectors.sln: use correct configuration for Debug

Before, the Release target got incorrectly assigned to the Debug configuration
for the library and test projects. This results in the library being compiled
into the Release dir when the solution is compiled on the command line
via msbuild.exe, while it should be compiled into the Debug dir.
dir.props: correctly enclose 'Exists' condition in single quotes

According to MSDN (http://msdn.microsoft.com/en-us/library/7szfhaft.aspx), the
single quotes can be left off for "simple alphanumeric strings or boolean values".
This is not the case here (it is a property), so we should use single quotes.

Note that MSBuild ignores this, but it results in a parser error on Mono's xbuild.
Merge pull request #286 from akoeplinger/patch-2

dir.props: correctly enclose 'Exists' condition in single quotes
Merge pull request #285 from akoeplinger/patch-1

System.Numerics.Vectors.sln: use correct configuration for Debug
Improve dictionary access
Microsoft.Win32.Primitives.csproj: Set AllowUnsafeBlocks to true

When building this project on Unix, the Interop.strerror.Unix.cs file
is included which contains p/invoke calls. We need to enable the
AllowUnsafeBlocks property to allow this.
Merge pull request #291 from akoeplinger/patch-1

Microsoft.Win32.Primitives.csproj: Set AllowUnsafeBlocks to true
Merge pull request #270 from alfaproject/xmldoc_dictionary

Improve dictionary access