Filter by restrictions

[mrinaldi]

Using a restriction in paket.dependencies, it wouldn't reference the dependencies depending on the restrictions it has.

Examples that were fixed:
>= net35 would not be referenced when paket.dependencies has a >= net40 restriction.
>= net35 < net452 would not be referenced when paket.dependencies has a >= net40 restriction.

Moreover, it would not filter at all dependencies when ranged restrictions were used in paket.dependencies.

Here is a small repro:

framework >= net45
source https://nuget.org/api/v2

nuget Microsoft.Owin.Host.SystemWeb ~> 2.1

Running paket install would generate the following incorrect paket.lock

FRAMEWORK: >= NET45
NUGET
  remote: https://nuget.org/api/v2
  specs:
    Microsoft.Owin.Host.SystemWeb (2.1.0)

On the other hand, the below file would also generate an incorrect paket.lock

framework >= net45 < net46
source https://nuget.org/api/v2

nuget Microsoft.Owin.Host.SystemWeb ~> 2.1

FRAMEWORK: >= NET45 < NET46
NUGET
  remote: https://nuget.org/api/v2
  specs:
    Microsoft.Owin (3.0.1)
      Owin (>= 1.0)
    Microsoft.Owin.Host.SystemWeb (2.1.0)
      Microsoft.Owin (>= 2.1.0) - framework: >= net40
      Microsoft.Web.Infrastructure (>= 1.0.0.0) - framework: net40
      Owin (>= 1.0) - framework: >= net40
    Microsoft.Web.Infrastructure (1.0.0)
    Owin (1.0.0)

This is the correct paket.lock for both cases:

FRAMEWORK: >= NET45
NUGET
  remote: https://nuget.org/api/v2
  specs:
    Microsoft.Owin (3.0.1)
      Owin (>= 1.0)
    Microsoft.Owin.Host.SystemWeb (2.1.0)
      Microsoft.Owin (>= 2.1.0) - framework: >= net40
      Owin (>= 1.0) - framework: >= net40
    Owin (1.0.0)