Document that barrier is currently not compatible with synergy

[p12tic]

Fixes issue #62. This just documents the current state of affairs without trying to imply anything about the future.

[walker0643]

I see that you're trying to mitigate confusion with this patch and I don't disagree. There are a couple arguments against....

1. We don't want to say "Barrier isn't compatible with Synergy" or even "isn't compatible at this time" because we don't want people to assume that it's still true after we (hypothetically) have changed it just because they read it somewhere once. As I said in the issue you referenced, it may change now that Symless has moved back to the 1.x branch. In the very least I don't want to rule it out.

2. Removing compatibility with Synergy was a conscious choice made for reasons (TM). Barrier may have been born from Synergy (which was born from CosmoSynergy) but it has gone its own way since (and so has Synergy). Especially in the main site readme we don't want to introduce the idea that "Barrier isn't compatible with Synergy" because the real message should be "Barrier isn't Synergy".

[p12tic]

OK, agreed.