Merge remote-tracking branch 'origin/master'

Update version to 1.2.6

Fix #29

Update version to 1.2.4, add setCloseable(boolean) to fix #26

Update dependency for 1.8.8 for better support: fixes #24 and #25

Update README.md to add 1.13 version

Fix #13 (I hope, not tested yet)

Update build.gradle

Change version to 1.1.3, disallow Shift + Click to put an item into

an inventory.

Replace javafx Pair by lang3 one.