btn-outline is misleading

[poldiwa]

I don't know what would be the effect to the framework but I think .btn-outline should be .btn-flat, and maybe let's keep the .btn-outline used by bs

[sesemaya]

Agree that it is probably better to have a .btn-flat selector (and documented in Material section of the doc site), but not sure what to do with .btn-outline since Material Design does not specify anything remotely similar.

I think for now I will keep .btn-outline as it is now and .btn-flat will behave in the same way.