Allow any valid name for items

[mrlacey]

We currently enforce entered item names to start with a character "a-zA-Z" this is much more restrictive than are actually valid in C#. We should allow anything that's valid. While doing this for completion is nice, this is important for anyone using a language that requires Unicode characters, not just ASCII. As a temporary measure, the error message should be improved. "Only alphanumeric and '-' characters are allowed" isn't strictly true.

[crutkas]

Great idea but we need to know how VS actually does this then. Example is a - changes to _.

Class-1.cs becomes Class_1.

Also how does this possibly affect our generation ability for post processing

[crutkas]

this seems an easy win. @sibille thoughts for 3.0? we can ping the VS team here.

[sibille]

Ok for 3.0, but we need the insights from vs on what is allowed and what transformations are applied

[crutkas]

ask made