git,sharepoint,tfs,checkin,changeset
The SharePoint integration with TFS does not support git. That webpart will not work with git.
I've worked with VK API with javascript, but I think, logic is the same. TL;DR: Offset is a number of results (starting with the first) which API should skip in response For example, you make query, which should return 1000 results (lets imagine that you know exact number of results)....
I'd recommend against a custom TFS check in policy. They get evaluated on the client meaning a) they interfere with developer workflow b) they can get overridden on the client (and it can be difficult to get notifications when developers override the policy), and most importantly c) you need to...
tfs,tfs2012,visual-studio-online,checkin
You can if you install the power tools. They add a query policy. You can create and chose any query...
As the others have said, there is a conflict here. That can occur by pending a change on a version of the file that is not the latest and trying to check in. You can see the conflicts with QueryConflicts. You can also find a sample here.
dll,visual-studio-2013,tfs,checkin
As Daniel said in the comment, NuGet is the way to go for this. Instead of checking in the binaries to TFS, have your MySQL build publish the binaries to a nuget feed. Then have your Library solution "subscribe" to that NuGet feed.