Set master branch to 1.0.0-rc5 in prep for rc4 release.
SCHEMA-208, SCHEMA-211. KijiURI builder & exception.

SCHEMA-208. Convert KijiURIException to unchecked.
SCHEMA-211. KijiURIBuilder should default to "default" instance, not null.

Signed-off-by: Christophe Taton <taton@wibidata.com>