Rename ExportAttribute to DllExportAttribute

[batzen]

I guess the name "DllExport" more accurately expresses what is done, in comparison to "Export".

[MeikTranel]

The decision to name it Export instead of DllExport definitely was intentional, as i wanted to avoid the conflict with UnmanagedExports. I personally don't think reving to a next major version right now because of a very minor semantic flavor in type naming is warranted.
I do however get the reasoning: .NET calls its importing counterpart DllImport, thus the reverse makes sense.
Maybe we can do this in the timeframe of a 1.0 release. You can always do

  using DllExportAttribute = NXPorts.Attributes.ExportAttribute;

in the meantime.

[filmor]

You are at 0.1, I don't see any problem with changing the name now. No one is expecting API stability from a pre 1.0 library.