L-systems treegen code tweaks.
Improved faces shading with and without shaders.
Fix issue #1275 - wielded index greater than inv size.
Remove not really used guiTextInputMenu
Fix issue #1275 - one more missing check.
Update buildbot scripts and add 64-bit buildbot
Make dropdown formspec elements send their value same style as buttons on change
Fix bounding rect for formspec elements label vertlabel and checkboxes
Add tooltips for button, imagebutton and checkbox.