Make install more flexible by removing `usr' from fix install path
Make install more flexible by removing `usr' from fix install path

- Allow specifying an install path that does not contain a `usr' directory
- If not provided, install path still default to `/usr'

Signed-off-by: Tristan Lelong <5c5d0812499afb9ceb483c77486336a24a013b40@blunderer.org>

mahmudur85/libroxml,gergap/libroxml,gergap/libroxml,mahmudur85/libroxml,mahmudur85/libroxml,gergap/libroxml,sartura/libroxml,mahmudur85/libroxml,sartura/libroxml,gergap/libroxml,sartura/libroxml,sartura/libroxml,gergap/libroxml,mahmudur85/libroxml,sartura/libroxml