Exceptions when no solution

[huguesv]

VS 2015, Web Essentials 2015 0.5.168

Start VS, no solution opened. Drag & drop a markdown file from windows explorer onto VS. At this point, solution explorer shows `Solution 'Solution1' (0 projects)"

Here are 3 different commands that are causing exceptions. They all should be disabled when editing a markdown file with no solution opened.

From main menu, Web Essentials, Create solution settings

Result:

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Microsoft Visual Studio
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Path cannot be null.

Parameter name: path
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OK   
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From main menu, Web Essentials, Create color palette

Result:

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Microsoft Visual Studio
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File name cannot be null.

Parameter name: destFileName
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OK   
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From main menu, Web Essentials, Add markdown solution stylesheet

Result: VS crashes and restarts