Fix math.random() to handle floats properly

Floats should be turned to integers in math.random().

For instance: math.random(0, 0.5) should always return 0.
Merge pull request #29 from elisee/randomfloat

Fix math.random() to handle floats properly
fix bug that does not allow semicolons after return or break statements
Never add a nil value to a table

myTable[key] = nil should never add key/nil to the table's objs
Merge branch 'master' into table_assign_nil
Merge branch 'master' into craftstudio
Merge branch 'table_assign_nil' into craftstudio