Fix: merge augmentation function docs

See #200

Merge the augmentations of the same target, as if they were defined
in the same augmentation.

The line and documentation of the augmentation itself are the ones
of the first augmentation declared, since merging docs can results
in not meaningful text.
Fix: reference to an overloaded function

Fixes bug #202 by raising a `AmbiguousFunctionReferenceException` when
trying to reference an overloaded function without providing arity,
using ether `fun(name, module)` or the `^` shorthand.
Code formating
Code formating
Merge pull request #203 from yloiseau/fix/RefToPolymorph

Fix: ambiguous reference to an overloaded function
Merge pull request #201 from yloiseau/bug/DocWhenMoreAugment

Fix: merge augmentation function docs