Compiler now mentions which file has a duplicated module. Fixes #2131
Fix two test cases
Fix compile error during boostraping
Removed superfluous 'be'
Merge pull request #2241 from stoft/master

Grammar, removed superfluous 'be'
Merge pull request #2240 from gmcabrita/fix-duplicated-module

Improve compiler message when duplicated modules are detected
Hide module's location attribute