support for 'eclipse-like' worksheet files (with only object in a file)
(cherry picked from commit 72bd843)
(cherry picked from commit 895522e)
refactoring
(cherry picked from commit ad29c2f)
(cherry picked from commit ab69d9f)
#SCL-6724 fixed {bad vars}
(cherry picked from commit 8a255f5)
(cherry picked from commit a07707b)
proper print for assignment statements (expression with type instead of 'Unit')
(cherry picked from commit c3269ff)
(cherry picked from commit 1a463c4)
Worksheet Stop Action
(cherry picked from commit 507cc3d)
(cherry picked from commit 8ea4a6c)