Flat module import namespace causing collisions

[Andrej Mitrovic]

Import doesn't behave like include at all, and it doesn't cater to C++
programmers.

See:
http://www.d-programming-language.org/module.html
Alternatively, TDPL.

Always use module names. If something conflicts, use selective
imports, or aliases, or static imports if you really want to avoid
clashes. You can even use function-local imports.