:break command should recognize also nonexported top level symbols in qualified IDs

[phercek]

When a breakpoint is defined for a qualified function name ( ( conid . )+ varid ). Then the name should be found even when it is not exported (i.e. when varid is not in the export list).
The qualification ensures no ambiguity can happen so it should be allowed since it is line number independent which means breakpoint definitions sourced with ":." would be more robust against code modifications.

[phercek]

Actually it would be cool if function names of the form ( conid . )* ( varid . )* varid could be recognized too.
The identifer can have a sequence of varids at the end. The idea is to identify a function which is defined in a where clause (or even a let clause (the first let function with given name)).
E.g. for this source file:

fn s = 'a' : add s
  where add = (++"z")

it could look like :break Main.fn.add and it would be tha same as :break 2 (breakpoint on 'add').