CallableBuilder ceylon/ceylon.language#217: add reified generics to callables
Test for callable reified generics for ceylon/ceylon.language#217
Updated test .src now that callables support reified generics: ceylon/ceylon.language#217
Added --encoding options to ceylondoc and the compiler #1086
CeyloncFileManager: default to UTF-8 encoding #1086
CeylondFileManager: go with platform encoding as a default after all #1086

After discussion, we decided the platform encoding default was the least surprise
Added "encoding" option to the ant tasks for compile, compile-js and doc.
Moved handling of common option to LazyCeylonAntTask.