Replace Context#in_function? and #in_unspec_block? by generic methods
Replace Context#in_function? and #in_unspec_block? by generic methods

This commit replaces Context#in_function? and #in_unspec_block? with
more geenric #in? and #innermost methods. This way we won't need to add
more #in_xxx? methods with various skipping semantics to Context in the
future.

yast/y2r