The CMake enable/disable flags as currently structured are a confusing mix of
WITH, WITHOUT, and USE with odd defaults. This changes the flags to consistently
use WITH and default the build options to everything enabled.
The CMake option OPENCV_JAVA_INSTALL_DIR can be set to the location
to search for the jar file. Note that the file name cannot be
changed, as, after checking several Linux package repositories,
that seems to be constant across all of them.
Fixes#2346.
