Added btn_special to SQL table button_view
Fixed doc block for BMButton
Added logic to disable buttons with btn_special == 1
Merge remote-tracking branch 'upstream/master' into 489_disable_btn_specials

Manually resolved conflicts in:
	src/engine/BMButton.php
Merge pull request #535 from blackshadowshade/489_disable_btn_specials

Disable buttons with button specials