fixed a bug that context menu goes outside the script region, causing scrollbar showing up. (#857)
fixed a bug that context menu goes outside the script region, causing scrollbar showing up. (#857)

This is because the position of context menu is determined by its height + the mouse y position;
When this max-height is in effect, it prevents blockly to calculate the actual height of the menu with menu items.

see https://github.com/LLK/scratch-gui/issues/111
sclements/scratch-blocks,gengshenghong/scratch-blocks,sclements/scratch-blocks,gengshenghong/scratch-blocks,griffpatch/scratch-blocks,LLK/scratch-blocks,LLK/scratch-blocks,LLK/scratch-blocks,gengshenghong/scratch-blocks,sclements/scratch-blocks,LLK/scratch-blocks,griffpatch/scratch-blocks,griffpatch/scratch-blocks,griffpatch/scratch-blocks,LLK/scratch-blocks,griffpatch/scratch-blocks,sclements/scratch-blocks,sclements/scratch-blocks,gengshenghong/scratch-blocks,gengshenghong/scratch-blocks