CxxWrap v0.15.1

Diff since v0.15.0

Merged pull requests:

• Add breaking changes for v0.15 (#417) (@barche)
• Add StdFill (#420) (@PraneethJain)
• Add support for dynamic casting on the Julia side (#427) (@barche)
• Test conditionally on ranges (#428) (@barche)
• Set version to v0.15.1 (#429) (@barche)

Closed issues:

• Release v0.15 (#416)
• StdVector of pointer with CxxWrap 0.15 (#419)
• CxxWrap 0.15.0 shared library loader is broken (#421)
• Double registration error (#422)