Some bug fixes and tweaks

Bug in the code flipped jump and case value of the switch op, remove dangling in_switch key, and add a formal "case" op-type and changed some strings back to "static" from "R_API" (https://github.com/radare/radare2/issues/1198).  Also added comments for appropriately handling the misreported caseop in the java_op function.  Note this is only used when doing sequential disassembly without following control flow in code.