More jigsaw spec clarifications

[Jonathan Gibbons]

Thank you for the preceding round of discussion and spec-updates.

The compile-time errors are all assertions that can be evaluated by 
examining an individual module declaration. Do you envisage specifying 
any compile-time errors arising from examining the set of observable 
module declarations.   For example, the restriction on duplicate views 
within a module declaration could be extended to be a restriction on 
duplicate observable views.  And, what about different modules trying to 
export the same package?

Separately, in the restrictions on the class names for entry points and 
service implementations, is it expected that the class names must be 
declared in the module declaring the entry point or service, or can the 
class names be found in the (re-)exports of any of the required modules?

-- Jon