Fix isWeaklyIsolated for interfaces

Interfaces are aggregate types, but their FieldTypeTuple is a tuple containing
exactly themselves. This causes an infinite recursion in isWeaklyIsolated.
Since the implementation of an interface is not known at compile time,
isWeaklyIsoleted must be false for interfaces.

Signed-off-by: Luca Niccoli <lultimouomo@gmail.com>
Fix compilation on DMD 2.064.
Ignore apt-get errors.
Fix compilation of the libev driver.

The timer functionality has been commented out for now.
Merge pull request #602 from lultimouomo/fixIsWeaklyIsolated

Fix isWeaklyIsolated for interfaces
Add Path.toHash for DUB compatibility.