Raise AugeasRuntimeError in newer APIs (#52)
Raise AugeasRuntimeError in newer APIs (#52)

Instead of raising RuntimeError when an augeas API fails, use the
AugeasRuntimeError subclass so all the details of the augeas error are
available to users.

Applies 927a25c0729dc88246b44f1b4911c8034ea32cb4 to the newer APIs
introduced with commits dca8493535edd5ae6de788ed9a86c6c05f26fd3f and
6cecd44f5c2e91451d5357880187536bbe045903. This also removes the
printing of the error code when only 0/1 are possible values, and
fixes the mentioned API in one message.
hercules-team/python-augeas,hercules-team/python-augeas