Update dependencies with fixes for SDK changes

[lanaklein14]

Re-opening #232 with some additional fixes which are causing build.bat to fail.

• Language.Unknown no longer exist in FFXIV_ACT_Plugin.Common Version 2.6.2.0
• StringHelper is no longer supported in FFXIV_ACT_Plugin.Common Version 2.6.2.0

Also updated the framework version for AddonExample.

[quisquous]

@ngld Sorry for ping, but would you consider merging this? Are you building against an older version of the ffxiv plugin?

[ngld]

I generally only update the references when I need something that's not available in the old version. If I require a too recent version, it can cause ACT to disable OverlayPlugin if a player updates OverlayPlugin before the FFXIV plugin or sometimes for users of the KR or CN versions (since their version number sometimes lags behind).

For example, the current KR version number is 2.1.3.0. If I merge this change, it'll most likely break OverlayPlugin for all KR users without providing any other benefit (as the current build still works with the latest FFXIV plugin).

[quisquous]

Ok, I see what the issue is on my end. Fetch deps doesn't complain if the ACT plugin is newer, and so I was having the above errors that this is trying to fix.

I think it would still be nice to land the AddOnExample fix (for .net framework) and the other code changes that make it forward-compatible to the new ACT plugin.