Allow building gui plugin for multiple architectures via gradle pluginDist-windows-x86, pluginDist-linux-x86_64, etc.
Multiarch plugins prep; relates to syncany/syncany#204
Merge commit 'c484c0c5d9f781aee017efa0a404a5ae1baac1bb' into feature/multiarch
Squashed 'core/' changes from 8d7beb3..abb737c

abb737c Multiarch plugins; relates to #204
9739932 Merge pull request #246 from vwiencek/feature/prepgui
a4805ba make distinction between arch and os
306aafc add environment parameter to pluginOperation modify EnvironmentUtil to make it more consistent

git-subtree-dir: core
git-subtree-split: abb737cfaf6fe048cb8dbdd84b73a4c8aea3381a
Update Travis recipe
Add travis credentials
Squashed 'core/' changes from abb737c..535c35e

535c35e Allow multiple JAR uploads in plugins

git-subtree-dir: core
git-subtree-split: 535c35e1788773b68c72de539740b7916a0a5d74
Merge commit '06a3b2b8e76e252928e3f826cb79dc038c381337' into feature/multiarch